How do you calculate percent recovery during recrystallization?
Percent recovery = amount of substance you actually collected / amount of substance you were supposed to collect, as a percent.
So another way of putting it:
Percent Recovery = (pure/impure) x 100
Let's say you had 10.0g of impure material and after recrystallization you collected 7.0 g of dry pure material. Then your percent recovery is 70% (7/10 x 100).
You need to make sure you material is dry or else the mass will be more than it actually is. That's why students sometimes calculate percent recoveries greater than 100% (which is impossible).

An expression that is used to represent the number of pennies is; 2n - 7

Algebraic word problems are defined as questions that require translating sentences to equations, then solving those equations. The equations we need to write will only involve basic arithmetic operations.

Now, we are told that;

Number of pennies  is 7 less than twice the number of nickels.

Thus. if n represents the number of nickels, then we can say that;

Number of Pennies = 2n - 7

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Answer: 5

Step-by-step explanation:

Opposite angles of parallelograms are always equal, thus resulting in the equation, 20 + 2x = 6x simplified to 20 = 4x, so x is equal to 5. Hope this helps!

Answer:

The answer is a) 5

Step-by-step explanation:

The two solutions of the linear equation are:

(0, 2)

(3, 1)

And a coordinate pair that is not a solution is:

(0, 5)

Here we have the linear equation:

x + 3y = 6

And we want to find two ordered pairs that are solutions.

To find them,wecan evaluate in two values of x and then find the correspondent values of y.

if x = 0

0 + 3y = 6

y = 6/3 = 2

if x = 3

3 + 3y = 6

3y = 6 - 3

3y = 3

y = 3/3 = 1

So the two solutions are (0, 2) and (3, 1)

And a point that is not a solution can be one with the same x-value than one of the above ones but a different y-value, like (0, 5)

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Answer: 24

Step-by-step explanation: 6*4=24

4+4+4+4+4+4=24

Answer:

she paid $1.50 / 1lb

Step-by-step explanation:

6lbs divided by $4 = 1.50 or $1.50 / 1lb

The values of x make the statement true are x = 9 X = -9.5 x = -9 and x = -10

From the question, we have the following parameters that can be used in our computation:

x-9.5 = a negative number

Using the above as a guide, we have the following:

x - 9.5 < 0

Make x the subject

x < 9.5

This means that the values of x are less than 9.5

From the options, we have:

x = 9 X = -9.5 x = -9 and x = -10

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Answer:

B

Step-by-step explanation:

Rise over run should be 4 rise and 5 to the side run

Answer:

Step-by-step explanation:

The last one (placed below)

Just take two random points (x1,y1) and (x2,y2) from the graph and calculate the slope according to the expression:

[tex]m=\frac{y2-y1}{x2-x1}[/tex]

The graph placed below, passes through the points (5,4) and (0,0). So if we replace these coordinates within the formula:

[tex]m=\frac{5-0}{4-0}=\frac{5}{4}[/tex]

Answer:

(3c - 2)(c - 6)

Step-by-step explanation:

Quadratic Formula:

ax^2 + bx + c

a = 3 and c = 12

a * c --> 3 * 12 = 36

b --> -20

Two numbers that multiply to get 36 and added together get -20 are -18 and -2.

-18(-2) = 36

-18 + (-2) = -20

[tex]\frac{-18}{3c} = \frac{-6}{c}[/tex], [tex]\frac{-2}{3c}[/tex]

(c - 6)(3c - 2) = 3c^2 - 20c + 12

The measures of the numbered angles in rhombus DEFG are m ∠ 1 = m ∠ 2 = m ∠ 4 = 27°, m ∠ 3 = 90° and m ∠ 5 = m ∠ 6 = 63°

A flat shape with 4 straight sides that are all equal length. Also opposite sides are parallel and opposite angles are equal. It is a type of parallelogram.

Given is a rhombus DEFG, we need to find the measures of the numbered angles,

We know that, diagonals of a rhombus bisect each other at right angle, and also bisects the vertex angles,

Also, the opposite angles are equal,

Therefore,

m ∠ 1 = m ∠ 2 = m ∠ 4 = 27°

m ∠ 3 = 90°

m ∠ 5 = m ∠ 6 = 90° - m ∠ 1

m ∠ 5 = m ∠ 6 = 90° - 27° = 63°

m ∠ 5 = m ∠ 6 = 63°

Hence, the measures of the numbered angles in rhombus DEFG are m ∠ 1 = m ∠ 2 = m ∠ 4 = 27°, m ∠ 3 = 90° and m ∠ 5 = m ∠ 6 = 63°

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Answer:

1188

Step-by-step explanation:

12x42 + 18x38  = 1188

The solutions to the expressions using laws of exponents are;

17) y^(19/28)

18) 1/a^(5/9)

The product rule of exponents states that "To multiply two expressions with the same base, add the exponents while keeping the base the same". Thus;

y² × y³ = y²⁺³

= y⁵

17) y^(3/7) × y^(1/4)

Applying product rule of exponents gives;

y^(³/₇ + ¹/₄)

= y^(19/28)

18) The negative exponent rule states that: To convert any negative exponent into positive exponent, the reciprocal should be taken." Thus;

x⁻³ = 1/x³

Thus;

a^(-5/9) = 1/a^(5/9)

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Answer:3y +=7  

=>3y-7-x

 =>y=(7-x)/3                               Step-by-step explanation:Solve for 'y' means, solve the equation to get the value of y and in terms of ,x means value of y not necessarily in pure constant form,but in the form of x.

The measures of angles in similar triangles are ∠ F = 22°, ∠ G = 75° and ∠ H = 83°

Similar triangles have the same corresponding angle measures and proportional side lengths.

Given that, Triangle ABC is similar to triangle FGH, we need to find the measures of the angles,

The sum of interior angles of a triangle = 180°

Considering Δ ABC,

∠ A + ∠ B + ∠ C = 180°

∠ C = 180°-(22°+75°)

∠ C = 83°

Since, we know that the similar triangles have congruent corresponding angles,

Therefore,

∠ A = ∠ F, ∠ B = ∠  G and ∠ C = ∠ H

Therefore, the measures of angles in Δ FGH are ∠ F = 22°, ∠ G = 75° and ∠ H = 83°

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Discrete variables are a subset of variables that have a limited range of values. A variable that counts how many kids a family has, for instance, can only be a whole number, such as 0, 1, 2, etc.

Discrete variables, like integers or categories, are a form of variable that can only take specified, distinct values. For instance, a discrete variable is the number of siblings a person has because it can only be 0, 1, 2, 3, etc.Discrete variables are a subset of variables that have a limited range of values. A continuous variable, on the other hand, can accept any value within a range.Whole numbers like 0, 1, 2, 3, and so forth are frequently used as discrete variables. The number of kids in a household, the number of products in a shopping cart, or the number of individuals in a room are all examples of discrete variables.

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The amount of State withholding tax is, $20.65 and the amount of Federal withholding tax is, $17.7.

A percentage is a value per hundredth. Percentages can be converted into decimals and fractions by dividing the percentage value by a hundred.

Assuming the State withholding tax to be 7% and the Federal withholding tax to be 6%.

Given, A  person made $295 last week.

Therefore, The amount of Federal withholding tax is,

= $(6/100)×295.

= $17.7.

And, The amount of State withholding tax is,

= (7/100)×295.

= $20.65

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The sides of the rectangle are

the codes are CFID

The unknown part of the rectangle is solved using division of polynomial and the check is completed by multiplication of the polynomial involved

checking for the correct answers

1. 2(x + 5)(x - 1) = (2x + 10)(x - 1)

2x² - 2x + 10x - 10

2x² + 8x - 10

2. 3(x - 1)(x + 6) = (3x - 3)(x + 6)

3x² + 18x - 3x - 18

3x² + 15x - 18

3. 2(x + 1)(x - 5) = (2x + 2)(x  -5)

2x² - 10x + 2x - 10

2x² - 8x - 10

4. 5(x - 1)(x + 1) = (5x -5)(x + 1)

5x² + 5x - 5x - 5

5x² - 5

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Answer:

Step-by-step explanation:

In Stata, you can include fixed effects in a regression by using the "xtreg" command with the "fe" option. The "xtreg" command is used to fit a linear regression model with panel data, and the "fe" option tells Stata to include fixed effects in the model.

Here's an example of how to run a fixed effects regression in Stata:

xtreg y x1 x2 x3, fe

In this example, "y" is the dependent variable, and "x1", "x2", and "x3" are the independent variables. The "fe" option tells Stata to include fixed effects for each individual in the panel data.

Note that the fixed effects in this example are time-invariant, meaning that they are constant for each individual over time. If you have time-varying fixed effects, you can include them in the regression using the "xtreg" command with the "vce(cluster id)" option, where "id" is the variable indicating the individual in the panel data.

The volume of a cubic foot is equal to 29.9220779 US liquid quarts. This conversion factor is based on the definitions of the cubic foot.

So the volume of a cubic foot is equal to 29.9220779 US liquid quarts. This conversion factor is based on the definitions of the cubic foot as a unit of volume equal to a cube with sides that are one foot in length and the quart as a unit of volume in the US customary system.

The quantity of cubic feet can be multiplied by 29.9220779 to get the conversion to quarts. For instance, if you have a container with a 2 cubic foot volume, the quantity of quarts in that container would be:2 cubic feet multiplied by the US liquid quart density of 29.9220779 gives 59.8441558 US quarts. The volume of a cubic foot is equal to 29.9220779 US liquid quarts. This conversion factor is based on the definitions of the cubic foot as a unit of volume equal to a cube with sides that are one foot in length and the quart as a unit of volume in the US customary system.

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The values of x in f(x)=2x g(x)=2^x is x=2 and x=0.77.

The solution of an equation refers usually to the values of the variables involved in that equation which if substituted in place of those variable would give a true mathematical statement.

We are given that;

f(x) 2x and g(x)=2^x

Now,

To graph the functions on the same coordinate plane, we can plot some points and connect them with a line:

f(x) = 2x

(0, 0), (1, 2), (2, 4), (3, 6), ...

g(x) = 2^x

(0, 1), (1, 2), (2, 4), (3, 8), ...

To find the solutions to the equation f(x) = g(x), we need to set the two expressions equal to each other and solve for x:

2x = 2^x

x=2, 0.77

Therefore, the answer of the given equation will be x=2, 0.77

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Answer:

Option 2 Is Correct

Step-by-step explanation:

The following statements are true about the function and its graph:

The graph of the function is a parabola.

The graph contains the point (0, 0).

The graph does not contain the point (20, -8).

Option 1 is true because the function is a quadratic function, and all quadratic functions have a parabolic graph.

Option 2 is true because the y-intercept of the function is (0,0).

Option 3 is false because the function opens upwards

Answer:

1) 108    2) 72    3) 11

Step-by-step explanation:

1) since the angle of PNM is the same as PLM, then we can simply add 42 and 66 to get 108 degrees

2)since the total angle in parallelogram is 360, we can take away the two angles we do know. Those are PLM and PNM which are 108 each.

360-108-108=144

with the last two corners having the same angle, the remaining degrees are distributed evenly giving us 144/2 = 72

3)since the length of LM and PN are the same then we get the equation

2d = 22 which gives us d = 11

Answer: 0.20689655

Step-by-step explanation: because you take 12 divided by 58

The table of values is

X |f(x)

0 | -45

2 | -35

4 | -25

6 | -15

From the question, we have the following parameters that can be used in our computation:

f(x) = -5|x - 9|

We have the x values to be

x = 0, 2 4 and 6

Substitute the known values in the above equation, so, we have the following representation

f(0) = -5|0 - 9| = -45

f(2) = -5|2 - 9| = -35

f(4) = -5|4 - 9| = -25

f(6) = -5|6 - 9| = -15

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Answer: $3.32

Step-by-step explanation:

First arrange the given discrete values in ascending order.

$3.26, $3.28, $3.31, $3.31, $3.32, $3.34,$3.35, $3.38, $3.42

we will use the formula 1/2 x (n +1), where n is total number of discrete values which in this case is 9.

This formula doesn't give the answer of the second quartile, it tells which nth term in the arranged set will be the second quartile.

1/2 (9+1) = 5.

Now we will choose the 5th term of the ascending order set.

Second quartile is same as the median, that means you need the mid value.

The bearing of the bank from the swimming pool is 42 degrees south of west.

What is temperature ?

Temperature is a measure of how hot or cold something is. More specifically, it is a measure of the average kinetic energy of the particles that make up a substance. When the particles in a substance move faster, their kinetic energy increases, and the temperature of the substance goes up.

Temperature is usually measured in degrees Celsius (°C) or degrees Fahrenheit (°F), although in scientific contexts, the International System of Units (SI) unit of temperature is the kelvin (K). The Celsius scale sets the freezing point of water at 0°C and the boiling point at 100°C, while the Fahrenheit scale sets the freezing point of water at 32°F and the boiling point at 212°F. The kelvin scale sets the zero point at absolute zero (-273.15°C or -459.67°F), the theoretical temperature at which all molecular motion ceases.

According to given condition:

The bearing of the swimming pool from the bank is 138 degrees.

The bearing is the angle measured clockwise from the north direction.

Therefore, to find the bearing of the bank from the swimming pool, we need to add 180 degrees to the given bearing of 138 degrees and then subtract 360 degrees (a full circle) to get the bearing within the range of 0 to 360 degrees.

So,

Bearing of bank from swimming pool = (138 + 180 - 360) degrees = -42 degrees

Therefore, the bearing of the bank from the swimming pool is 42 degrees south of west.

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The equivalent to the statement the price decreased by 1/2% will be 0.995x. Thus, all options are incorrect.

The amount of any product is given as though it was a proportion of a hundred. The ratio can be expressed as a quarter of 100. The phrase % translates to one hundred percent. It is symbolized by the character '%'.

The percentage is given as,

Percentage (P) = [Final value - Initial value] / Initial value x 100

Let the price be 'x'. Then the equivalent to the statement the price decreased by 1/2% is given as,

⇒ (1 - 0.5 / 100) x

⇒ 0.995x

The equivalent to the statement the price decreased by 1/2% will be 0.995x. Thus, all options are incorrect.

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If the price elasticity of demand is equal to 0.02/0.1, then the demand for apples is inelastic and if the price elasticity of demand is equal to 0.2/5, then the demand for apples is elastic.

The price elasticity of demand is calculated using the midpoint method with formula:

Price Elasticity of Demand = (Percent Change in Quantity Demanded) / (Percent Change in Price)

The value of the price elasticity of demand tells us whether the demand for a product is elastic (sensitive to price changes), inelastic (insensitive to price changes), or unitary elastic (neither elastic nor inelastic). A value of price elasticity of demand greater than 1 indicates that the demand for the product is elastic, meaning that a small change in price leads to a large change in the quantity demanded. A value of price elasticity of demand less than 1 indicates that the demand for the product is inelastic, meaning that a small change in price leads to a small change in the quantity demanded.

If the price elasticity of demand is equal to 0.02/0.1, then the demand for apples is inelastic between points X and Y, meaning that a small change in price leads to a small change in the quantity demanded. If the price elasticity of demand is equal to 0.2/5, then the demand for apples is elastic between points X and Y, meaning that a small change in price leads to a large change in the quantity demanded.

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Answer:

140 ° , because it is vertically opp to angle 4 and angle 4 is corresponding 8 .

Answer: The solution of the system of equations is (x, y) = (-1, -2).

Step-by-step explanation:

We can solve this system of equations by using either elimination or substitution method. Here, we'll use elimination:

Adding the two equations, we get:

(3x + 7y) + (-3x + 9y) = -17 - 15

Simplifying the left side and right side:

16y = -32

Dividing both sides by 16:

y = -2

Now we can substitute y = -2 into either of the original equations and solve for x. Let's use the first equation:

3x + 7(-2) = -17

Simplifying:

3x - 14 = -17

Adding 14 to both sides:

3x = -3

Dividing both sides by 3:

x = -1

The mathematical expression that shows the number of math problem left for Ernest is 16-p

Linear expressions are expression that it's highest power in of it's variable is 1. Linear expression can have more than one variables.

Some of the examples of linear equations are 2x – 3 = 0, 2y = 8, m + 1 = 0, x/2 = 3, x + y = 2, 3x – y + z = 3.

Ernest has 16 math problem , he has solved p out of it.

To actually know the remaining math problem left, we subtract the number he has done from the number of original problem

This means the number r of problem left = 16-p

therefore the expression is 16-p

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The process in which a number is changed, such as by adding, subtracting, dividing or multiplying is called mathematical operation.

A mathematical operation is a process that changes a number in some way. The most common mathematical operations are:

Addition is adding two or more numbers together to find their sum.

Subtraction is finding the difference between two numbers by subtracting one from the other.

Multiplication is finding the product of two or more numbers by multiplying them together.

Division is finding the quotient of two numbers by dividing one by the other.

In addition to these basic operations, there are also other mathematical operations such as modulo, exponentiation, and square roots.

These operations are used to perform various mathematical calculations and are fundamental to many areas of mathematics, including algebra, calculus, and geometry. They are also used in many real-world applications, such as in finance, engineering, and science.

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