Algebra - Two Questions
1. A system of linear equations is shown​ below as well as the first steps that Raffi is using to solve this system of linear equations by substitution. Choose the statement that best describes how Raffi is progressing toward a solution.

7x+y=4

3x−2y=3

Solution: Solve the first equation to obtain y=−7x+4. Substitute this into the second equation to get 3x−2⋅−7x+4=3.


2. Solve the following system by the substitution method.

2x−y=−4

−5x+3y=14

Answers

Answer 1

Answer:

The answer is below

Step-by-step explanation:

1) Below are the linear equations.

7x+y=4         (1)

3x−2y=3      (2)

The above linear equations are a system of equations. The substitution method is a technique for solving systems of linear equations.

Given that:

7x + y = 4

y = 4 - 7x

substitute y = 4 - 7x in equation 2, hence:

3x - 2(4 - 7x) = 3

3x - 8 + 14x = 3

17x = 3 + 8

17x = 11

x = 11/17

Put x = 11/17 in y = 4 - 7x

y = 4 - 7(11/17)

y = -9/17

2) 2x−y=−4     (1)

 

−5x+3y=14     (2)

From equation 1:

2x−y=−4

y = 2x + 4

Put y = 2x + 4 in equation 2:

-5x + 3(2x + 4)  = 14

-5x + 6x + 12 = 14

x + 12 = 14

x = 2

Put x = 2 in y = 2x + 4:

y = 2(2) + 4

y = 8

Answer 2

Answer:

1. Raffi forgot to place the substituted expression in parentheses.

2. (2, 8)

Step-by-step explanation:

If you are taking the Solving Systems With Substitution Quick Check from Connexus here are all of the answers:

1. Solve one linear function in terms of one of its variables.

2. Substitute 3y from the second equation for x in the first equation.

3. Raffi forgot to place the substituted expression in parentheses.

4. Yes, because substituting the given ordered pair yields two true expressions.

5. (2, 8)


Related Questions

At the school carnival, the soccer team sold hamburgers and hot dogs. A person buying one hamburger and one hot dog will spend $17.65. The soccer team sold 22 hamburgers and 39 hot dogs and made $511.55. How much does each item cost?
A. hamburger:$7.25, hot dog: $10.40
B. hamburger: $8.39, hot dog: $8.39
C. hamburger: $8.83, hot dog: $8.82
D. hamburger: $10.40, hot dog: $7.25

Answers

i would like to say D

The cost of the hamburger and hot dog will be $10.4 and $7.25, respectively. Then the correct option is D.

What is a linear equation?

A relationship between two or more parameters that, when shown on a graph, produces a linear model. The degree of the variable will be one.

The linear equation is given as,

y = mx + c

Where m is the slope of the line and c is the y-intercept of the line.

At the school carnival, the soccer team sold hamburgers and hot dogs. A person buying one hamburger and one hot dog will spend $17.65. The soccer team sold 22 hamburgers and 39 hot dogs and made $511.55.

Let x be the cost of hamburgers and y be the cost of hot dogs. Then the equation will be

x + y = 17.65                ...1

22x + 39y = 511.55     ...2

Solve the equations, then we have

22(17.65 - y) + 39y = 511.55

388.3 - 22y + 39y = 511.55

17y = 123.25

y = $7.25

Then the value of x will be

x + 7.25 = 17.65

x = 17.65 - 7.25

x = $10.40

The cost of the hamburger and hot dog will be $10.4 and $7.25, respectively. Then the correct option is D.

More about the linear equation link is given below.

https://brainly.com/question/11897796

#SPJ2

can u explain the answer of c)ii)
plss:(​

Answers

Answer:

i) The probability of getting 50 cent coin is 5/18, or approximately 28%

ii) To scale the numbers up to let us have 65 fifty cent coins, there would be a total of 234 coins

Step-by-step explanation:

We are told the probability of choosing ten and 20 cent coins, and from that we can work out the probability for the 50 cent coin.  All we need to do is add up the other two probabilities and subtract them from 1.

[tex]p = 1 - (\frac{1}{3} + \frac{7}{18})\\p = 1 - (\frac{6}{18} + \frac{7}{18})\\p = 1 - \frac{13}{18}\\p = \frac{5}{18}\\[/tex]

So the chance of getting a 50 cent coin is five eighteenths, or approximately 28%

For the second question We are asked to find the total number of coins if there are 65 fifty cent coins. (I can't see the text below that, but presumably it's saying that the ratios will stay the same).

We can solve this by comparing the two ratios, with x as the total, and solving for x:

[tex]\frac{5}{18} = \frac{65}{x}\\5x = 65 * 18\\x = 13 * 18\\x = 234[/tex]

So to keep the same ratios and have 65 fifty cent coins, we would need a total of 234 coins.

Adam is going to make concerte He Is going to use 180kg of cement 375kg of sand 1090kg of stone Cement, sand, stones are sold in bags: 1 bag cement is 25kg 1 bag sand is 22.5kg 1 bag stone is 50kg Adam already has 8 bags of cement 19 bags of sand 29 bags of stones Work out what bags he needs to buy to make the concrete. Working must be shown

Answers

Answer:

The answer is "90 kg stone ".

Step-by-step explanation:

Adam's got:

[tex]\to 8 \times 25 = 200 \\\\\to 19 \times 22.5 = 427.5 \\\\\to 20 \times 50 = 1000 \\\\[/tex]

He's got enough sand and cement  

The stone value:

[tex]\to 1090-1000 = 90 \ kg[/tex]  

He has 2 stone bags.

I
3.) Write the equation of the line that passes through (0,3) and (1.-1) in standard form.

Answers

Given:

The points are (0,3) and (1,-1).

To find:

The equation of line passes through these points.

Solution:

Standard form of a line is

[tex]Ax+By=C[/tex]

We know that, if a line passes through two points [tex](x_1,y_1)[/tex] and [tex](x_2,y_2)[/tex], then the equation of the line is

[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]

The line passes through (0,3) and (1,-1), so the equation of the line is

[tex]y-3=\dfrac{-1-3}{1-0}(x-0)[/tex]

[tex]y-3=\dfrac{-4}{1}(x)[/tex]

[tex]y-3=-4x[/tex]

Adding 4x and 3 on both sides, we get

[tex]4x+y=3[/tex]

Therefore, the standard form of the line is [tex]4x+y=3[/tex].

I WILL GIVE BRAINLIEST !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
PLEASE

Answers

all real numbers so the answer is D

Answer:

D. All real numbers

Describe how you can tell whether a line’s slope is greater than 1, equal to 1, or less than 1

Answers

If the slope is greater than one, it would have a positive slope and it is moving vertically up the y axis.

If the slope is equal to one, Guessing that the y axis is counting by 1 you could tell the slope is 1 by looking to see if first, it is moving positively up the y axis or look at what points it is intersecting. If it's counting every 1 point (For example) If the start of the slope began on the origin (0, 0) than it should count (0, 0) - (1, 1) - (2, 2) - (3, 3) etc..

Now the more "confusing" one. if the slope is less than one it can be a flat line on the graph. Not negative nor positive, Its neutral. You can also tell if its positive if it is moving down the graph, Negatively.  or if it is moving into a different quadrant from. (0, 0)

The different fonts are the different answers, i hope this helped.

Madelyn buys 3 bottles of orange juice at the corner store for a total cost of $2.31. If each bottle costs the same amount, how much is each bottle of juice?

Answers

Answer:

cost of each bottle of juice is $0.77

Step-by-step explanation:

Let the cost of 1 bottle be $x

multiplying both side by 3

then cost of 3 bottle will be 3*$x = $3x

given that

total cost of 3 bottles =  $2.31

thus

3x = 2.31

dividing both side by 3

x = 2.31/3 = 0.77

Thus, cost of each bottle of juice is $0.77

Answer:

$0.77 for each bottle of juice

Step-by-step explanation:

Madelyn buys 3 bottles of orange juice at the corner store for a total cost of $2.31.

So,

2.31/3 = 0.77

Thus, $0.77 for each bottle of juice

-TheUnknownScientist

Number Eight: Simplify

Answers

Answer

dookie but

Step-by-step explanation:

dookie in my dookie x 3 =  dookie

What best describes the expression 6 over y? (1 point)

A. 6 times some number
B. 6 divided by some number
C. 6 minus some number
D. 6 more than some number
Brainliest goes to the first answer, thank you!

Answers

The answer is B. 6 over Y means 6 divided by a number.

Find the solution for the system of linear equations by substitution:
y = x
y = 2x − 4

Answers

Answer:

Asi takhle

..........

Please answer ASAP will mark brainliest. If a reflection leaves a point unchanged, which of the following must
be true (select all that apply):
1 The line of reflection must have a slope of 0.
2. The point must be the origin.
3. The line of reflection has a slope of 1.
4. The point lies on the line of reflection.

Answers

Answer:

4

Step-by-step explanation:

The graph shows the number of Calories burned running. How many Calories do you burn per​ minute?

Answers

11.2 you could do 112/10 or 22.4/2.

A supplier of digital memory cards claims that less than 1% of the cards are defective. In a random sample of600 memory cards, it is found that 3% are defective, but the supplier claims that this is only a sample fluctuation. At the 0.01 level of significance, test the supplier's claim that less than 1% are defective. Use the p-value method.

Answers

Answer:

The  decision rule is

Fail to reject the null hypothesis

The conclusion is  

    The is no sufficient evidence to support the claim that the less than 1% of the cards are defective

Step-by-step explanation:

From the question we are told that

     The sample size is  [tex]n = 600[/tex]

      The population proportion of defective samples is p =  0.01

       The sample proportion of defective samples is  [tex]\^ p = 0.03[/tex]

       The level of significance is [tex]\alpha = 0.01[/tex]

       

The null hypothesis is [tex]H_o : p = 0.01[/tex]

The alternative hypothesis is  [tex]H_a: p < 0.01[/tex]

      Generally the test statistics is mathematically represented as

                  [tex]t = \frac{\^ p - p }{ \sqrt{ \frac{p( 1 - p )}{n} } }[/tex]      

=>              [tex]t = \frac{0.03 - 0.01 }{ \sqrt{ \frac{0.01( 1 - 0.01 )}{600} } }[/tex]

=>              [tex]t = 0.00406[/tex]

From the z table  the area under the normal curve to the left corresponding to  0.00406   is

         [tex]p-value = P(Z < 0.00406 ) = 0.50162[/tex]

comparing the p-valve and the level of significance we see that the

           [tex]p-value > \alpha[/tex]     hence  

The  decision rule is

Fail to reject the null hypothesis

The conclusion is  

    The is no sufficient evidence to support the claim that the less than 1% of the cards are defective

What is the check digit(d) for the UPC bar code
7-25272-73070-d
A)8
B)3
C)4
D)2

Answers

B I hope this help I think it’s right

NEED HELP!!! Can someone help me with 5, 7, and 8???
Need this asap!!!
THANK YOU!!!

Answers

Answer:

5) 8/17 = .471

7) 8/17 = .471

8) 15/17 = .88

Step-by-step explanation:

hope that helps

Answer:

5. [tex]\frac{\sqrt{2} }{2}[/tex]

7. [tex]\frac{\sqrt{2} }{2}[/tex]

8.[tex]\frac{\sqrt{2} }{2}[/tex]

Step-by-step explanation:

angles in a triangle equal 180 degrees. it is a right angle triangle so one angle is 90 degrees. both the other two are 45 each

5. cos(d)=cos(45)

7. sin(f)=sin(45)

8.cos(f)=cos(45)

HELP ME PLEASE I HAVE BEEN ON THIS QUESTION FOR 5 YEARS NOW WHATS THE ANSWER???????

2+1=

(if y’all dont get the joke-)

Answers

The answer is number B

Is this correct please some one

Answers

Answer:

Yes this is right (Hope this helps)

Step-by-step explanation:

(Brainliest)

A band is paid $50 for performing at a restaurant. For each customer that eats at the restaurant, the band is paid $2. If the band made $142 in one night, how many customers ate at the
restaurant?

Answers

Answer:

There were 46 customers who ate at the restaurant.

Step-by-step explanation:

First we need to subtract the total by how much the ban was paid to perform.

$142 - $50 = $92

$92 ÷ 46 = $2

PLEASE ASAP, DONT LIE ABOUT THE ANSWER, I'LL KNOW.

Answers

Answer:

The answer is graph b

Step-by-step explanation:

If you look at the other graphs closely, you'll find that they are wrong because they are not in correlation with the inequalities given

I hope it helps

i need help, can you please help me?

Answers

Answer:

Y= 2/4x + -3

Step-by-step explanation:

Anybody know the answer

Answers

Answer:

8

Step-by-step explanation:

pytherogream triple or smth

17,15,8

225+64=289

What is the range of the function graphed below? ​

Answers

Answer:

__________-3<Y<4______________

Please help me and explain to me!

Answers

I believe the answer is 19.2 because you would have to do paythag. = a^2+b^2=c2 in this case it would be 7^2 + 10^2 = c
From there you would get the answer of 149, and you would have to square root it. When you square root 149 you get 12.2
12.2 + 7 = 19.2
You would add them together because you want to know the height before it broke.

Step-by-step explanation:

use phytagoras theorem to find the length of broken post

[tex] \sqrt{ {7}^{2} } + {10}^{2} [/tex]

[tex] \sqrt{49 + 100} [/tex]

[tex] \sqrt{149} [/tex]

[tex] = 12.2[/tex]

add the broken post with the standing

= 7 + 12.2

=19.2

Find the equation of the line.
Use exact numbers.
y =
x+

Answers

Answer: y= 2/3x+4

Step-by-step explanation:

Use the distributive property to multiply (2 w + 7)(2 w - 7).​

Answers

Answer:

[tex]4w^{2} -49[/tex]

Step-by-step explanation:

Expand  (2w+7)(2w−7)

2w(2w-7)+7(2w-7)

2w(2w)+2w*-7+7(2w-7)

2w(2w)+2w*-7+7(2w)+7*-7

PLS HELP ASAP

Choose the (factored) form of the given equation.



6 x2 + 2 x - 8 = 0


1. (6 x - 8)( x + 1) = 0

2. (6 x + 8)( x - 1) = 0

3. (6 x + 1)( x - 8) = 0

Answers

Answer:

1,=(6x-8)(x+1)

=6x²+6x-8x-8

=6x²-2x-8

2,=(6x+8)(x-1)

=6x²-6x+8x-8

=6x²+2x-8

3,=(6x+1)(x-8)

=6x²-42x+x-8

=6x²-41x-8

Answer:

second option

Step-by-step explanation:

Expand the factors using FOIL

1

(6x - 8)(x + 1) = 0

6x² - 2x - 8 = 0 ≠ 6x² + 2x - 8

2

(6x + 8)(x - 1) = 0

6x² + 2x - 8 = 0 ← True

3

(6x + 1)(x - 8)

= 6x² - 47x - 8 = 0 ≠ 6x² + 2x - 8 = 0

Thus the factored form is

6x² + 2x - 8 = 0

(6x + 8)(x - 1) = 0 → second option

Simone has a collection of coins consisting of 1 quarter, 1 nickel and 1 penny. Using at least two coins from the collection, how many different sums of money are possible

Answers

Answer:

4 different sums

Step-by-step explanation:

There are two ways to form a sum: either by leaving out one coin or by not leaving out any. There are three options if we want to leave out one coin, and obviously only one way to not leave out any, so that gives us our answer of [tex]$3+1=\boxed{4}$[/tex] .

Hope this helped! :)

The difference sum of money that should be possible is 4.

The following information should be considered:

There are two ways to form a sum i.e. either by leaving out one coin or by not leaving out any. There are three options if we want to leave out one coin, and obviously only one way to not leave out any, so that gives us i.e.

= 3 + 1

= 4

Learn more: brainly.com/question/16911495

5x³y+10xy²


I will mark brainlest ​

Answers

5x³y+10xy²

we can factorise

5xy(x^2+2y)

5xy(x²+2y) ⬅️ we got this by taking common

ABCD is a trapezium with AB parallel to DC.
DC= 15 cm and AB= x cm
The perpendicular distance between AB and DC is 3 cm less than the length of AB. The area of ABCD is 75 cm square.
i) show that x2 + 12x - 195= 0

Answers

Answer:

Step-by-step explanation:a or b ?

Help, I have to turn this in tomorrow I need to know if this is right.

Answers

Answer:

yes, that's correct!

Step-by-step explanation:

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