Answer:
Using Descartes' Rule of Signs, we observe whether each consecutive term has a + or - sign:
f(x) = 3x4 − 5x3 − x2 − 8x + 4
Signs are: + - - - +
There are 2 sign changes (from +3 to -5, then from -8 to +4). This means that there are either 2 or 0 positive roots. (We take the number of sign changes, which is 2, and subtract by 2s to get all possible numbers of positive roots.)
For negative roots, we first invert all the odd-powered terms in f(x):
3x4 + 5x3 − x2 + 8x + 4
Signs are: + + - + +
There are 2 sign changes, from +5 to -1, and from -1 to +8. Therefore, there are either 2 or 0 negative roots.
Since the overall degree of f(x) is 4, the total number of roots must sum up to 4. There are either 2 or 0 positive roots, and 2 or 0 negative roots, and everything that remains will be a complex root. The possibilities are:
2 positive, 2 negative, 0 complex
2 positive, 0 negative, 2 complex
0 positive, 2 negative, 2 complex
0 positive, 0 negative, 4 complex.
Therefore we can have either 0, 2, or 4 complex roots.
The correct answer is the last choice.
Mike wants to fence in part of his backyard. He wants the length of the fenced-in area to be at least 20 feet long, l ≥ 20. He has 200 feet of fencing. The inequality that models the possible perimeter of the yard is 2l 2w ≤ 200. Which are possible dimensions for Mike’s backyard? Check all that apply. W = 50 ft; l = 10 ft w = 10 ft; l = 50 ft w = 20 ft; l = 60 ft w = 90 ft; l = 30 ft w = 50 ft; l = 40 ft.
The inequality that models the possible perimeter of the yard is 2(l + w) ≥ 200
The possible dimension of the width is 90 feet
The formula for calculating the perimeter of the fence is expressed as:
P = 2(l + w)l is the length of the fencew is the width of the fenceIf he has 200 feet of fencing, then:
2(l + w) ≥ 200
If the length of the fenced-in area to be at least 20 feet long, the equation becomes:
2(20 +w) ≥ 200
40 + 2w ≥ 200
2w ≥ 200 - 40
2w≥ 160
w≥ 80
Hence the possible dimension of the width is 90 feet
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A truck left a station at 6:00am traveling at a rate of 45km/h. A van left the same place 2 hours later heading in the same direction at a rate of 54km/h. At what time will the van catch up with the truck?
The Van would catch up with the truck at 6:00 pm
Speed is the ratio of distance travelled to time taken. It is given by:
Speed = distance / time
Let us say the van catch up with the truck after t hours at a distance d.
For the truck:
45 = d/t
d = 45t
For the Van:
54 = d / (t - 2)
d = 54t - 108
45t = 54t - 108
9t = 108
t = 12 hours
The Van would catch up with the truck at 6:00 pm
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Answer:
The Van would catch up with the truck at 6:00 pm
Speed is the ratio of distance travelled to time taken. It is given by:
Speed = distance / time
Let us say the van catch up with the truck after t hours at a distance d.
For the truck:
45 = d/t
d = 45t
For the Van:
54 = d / (t - 2)
d = 54t - 108
45t = 54t - 108
9t = 108
t = 12 hours
The Van would catch up with the truck at 6:00 pm
Consider the graph of the equation y=(x–9)? – 7. Compared the graph of y=x”, how has the vertex been shifted (left/right and/or up/down) and by how many units?
Answer:
Shifted to the right by 9 units, and down by 7 units
Step-by-step explanation:
y=x is the origin.
(x-9) shows that the graph has moved 9 units to the right, as what is inside the parentheses indicates the opposite direction
(you can be able to review why this is from online resources or you can ask your teacher)
the -7 shows that the graph moves 7 units down the graph, it's outside the parentheses, so it follows the same direction
let's sum up:
for this situation,
- what is inside the parentheses is the x
- what is outside the parentheses is the y
- the x-values direction shifts opposite from the sign (+/-)
- the y-values direction shifts like the sign (+/-)
So,
the vertex has been shifted to the right by 9 units, and down by 7 units compared to y=x.
Twelve is sixteen less than four times a number.
Mike makes and sells skateboards. If he has a cost of $6,200 per year plus a cost of $15 per skateboard, how many skateboards must he sell in order to make a profit if each skateboard sells for $35?
Answer: 310
Step-by-step explanation:
35-15= 20
6200 / 20 = 310
Answer:310
Step-by-step explanation:divide 6200 by 20 and it gives you 310
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Census data from a city of 150,000 residents produced the income distribution shown here: A distribution curve of income in thousands of dollars. The curve is right skewed with a mean between 50 and 100. Suppose that we were to take random samples of 100 residents from this population and calculate ˉ x as the sample mean income of the residents in each sample.
Using the Central Limit Theorem, it is found that the shape of [tex]\bar{x}[/tex] is approximately normal.
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.In this problem, the distribution is not normal, however the sample size is of 100 > 30, hence the Central Limit Theorem is applicable and the shape of [tex]\bar{x}[/tex] is approximately normal.
To learn more about the Central Limit Theorem, you can take a look at https://brainly.com/question/4086221
What is the perimeter of a rectangle whose length is twice the width? Width = 7 cm.
Answer:
42 cm is the perimeter
Step-by-step explanation:
Brainleast answer mo nalang
Answer:
P = 42 cm
Step-by-step explanation:
The perimeter (P) is the sum of the 4 sides of the rectangle with opposite sides being congruent.
Given width = 7 cm then length = 2 × 7 = 14
P = 7 + 7 + 14 + 14 = 42 cm
f(-3)
f(x)= 3 to the power of x
Find the sum of all solutions to the equation $3x(x+4) = 135$.
Answer:
-4
Step-by-step explanation:
3x(x + 4) = 135
3x² + 12x = 135
3x² + 12x - 135 = 0
On dividing by 3
x² + 4x - 45 = 0
x² + (9x - 5x) - 45 = 0
x² + 9x - 5x - 45 = 0
x(x + 9) - 5(x + 9) = 0
(x + 9)(x - 5) = 0
x = 5 & -9
Sum = -9 + 5
Sum = -4
The sum of the solutions of the given quadratic equation will be -4.
What is a quadratic equation?An algebraic equation of the second degree in x is a quadratic equation. The quadratic equation is written as ax2 + bx + c = 0, where x is the variable, and a must not be zero.
As per the given equation,
⇒ 3x(x + 4) = 135
Multiply the 3x as,
3x² + 12x = 135
3x² + 12x - 135 = 0
Divide the above equation by 3 as
3x²/3 + 12x/3 - 135/3 = 0
x² + 4x - 45 = 0
x² + 9x - 5x - 45 = 0
x(x + 9) - 5(x + 9) = 0
(x - 5)(x + 9) = 0
x = 5 and x = -9
Therefore the sum will be -9 + 5 = -4
Hence "The total of the quadratic equation's answers will be -4".
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the numbers 1 to 9 are randomly arranged to form a 9-digit number. what is the probability that the number obtained is divisible by 18?
(please write the solution)
Answer:
Hence the probability that the number is divisible by 18 is 4/9 or approx. 0.4444. or even 44.4%
Step-by-step explanation:
If we have 9 digits 1–9 placed randomly to form a 9-digit number without repetition and we want the probability of that number is divisible by 18, then we only need to look at the fact if it is divisible by 18, then it is also divisible by 2 and 9. Adding the digits 1–9 would give us the following (including checking for divisibility by 9):
(9 x 10)/2 =90/2 = 45
45÷9=5
By divisibility of 9, if the sum of the digits is divisible by 9, then the original number itself is divisible by 9. Since the number 45 is divisible by 9, we know that all the possible 9-digit numbers will be as well. The only thing we would have to look at is if it is even since the number has to be divisible by 2.
There are 9 digits of which 4 are even (2, 4, 6 or 8).
So the probability that the number is divisible by 2 is 4/9.
Hence the probability that the number is divisible by 18 is 4/9 or approx. 0.4444.
what is 174 divided by 74
Answer:
2.35
Step-by-step explanation:
Answer:
2.35
Step-by-step explanation:
I hope this helps you!
How much will is cost for 10 pencils and one notebook
Notebook $1.25
Pencil $0.50
Binder $2.15
Pen $0.80
Answer:
$6.25
Step-by-step explanation:
10 pencils = $0.5 times 10 = $5
$5 plus $1.25 (price of the notebook) = $6.25
If I make 2,500 dollars a minute.How much money will I make in 8 hours?
Answer:
1200000
Step-by-step explanation:
First, convert the 8 hours into minutes 8 hours * 60 minutes = 480 minutes
Then just do 2500 dollars * 480 minutes = 1200000
Answer:
$1,200,000
Step-by-step explanation:
We 1st multiply 2,500 by 60 due to 60 minutes being in 1 hour and get 150,000
We now know that in 1 hour you make 150,000 and to find out how much you make in 8 we then multiply 150,000 by 8 which equals $1,200,000.
I hope this helps have a great day and happy holidays :)
May I please receive help?
Answer:
24°
Step-by-step explanation:
(4y-4)+(180-52)+3y = 180°
4y-4+128+3y = 180
7y+124 = 180
7y = 56
y = 8
SO ∠x = 3y
∠x = 3(8)
∠x = 24
Answer:
24
Step-by-step explanation:
to find the measure of angle X we must first find y
An exterior angle of a triangle is equal to the sum of the opposite interior angle
angle wyz is an exterior angle and the opposite interior angles are w and x
this means that angle wyz = angle w + angle X
if angle wyz = 52 , angle X = 3y and angle w = 4y-4 then 52 = 3y + 4y - 4
note that we just created an equation that we can use to solve for y
we now solve for y using the equation we just created
52 = 3y + 4y - 4
combine like terms
52 = 7y - 4
add 4 to both sides
56 = 7y
divide both sides by 7
we're left with y = 8
Now to find the measure of angle X we simply plug in the value of y into 3y because angle X = 3y
angle X = 3y
y = 8
angle X = 3(8)
multiply 3 and 8 to get 24
angle X = 24
and we are done!
I want quick plsssss
[tex]3 \times \frac{1}{2} \\ \\ = \frac{5}{2} [/tex]
The sum and difference of two positive numbers are 15 and 5 respectively. Find the numbers.
[tex]x+ y =15~~...(i)\\\\x-y = 5~~...(ii)\\\\\text{(i) +(ii):}\\\\x+y+x-y = 15+5\\\\\implies 2x = 20\\\\\implies x = \dfrac{20} 2 = 10\\\\\text{(i)-(ii):}\\\\x+y -x +y = 15 -5\\\\\implies 2y = 10\\\\\implies y=\dfrac{10}2 = 5\\\\\text{Hence the numbers are 10 and 5}[/tex]
if candy canes cost .89 a dozen, how much would it cost to buy candy canes for a school with 300 students
Answer:
267
Step-by-step explanation:
Answer:
First dont give candie second keep for yourself third mock them 4th be greedy
Step-by-step explanation:
by buying candie from your own money nah waste on yourself
express the following fractions as the sum or difference of two fractions (x^2+y^2)/x^4
Answer:
[tex]\frac{1}{x^2}[/tex] + [tex]\frac{y^2}{x^4}[/tex]
Step-by-step explanation:
[tex]\frac{x^2 + y^2}{x^4}[/tex] = [tex]\frac{x^2}{x^4}[/tex] + [tex]\frac{y^2}{x^4}[/tex] = [tex]\frac{1}{x^2}[/tex] + [tex]\frac{y^2}{x^4}[/tex]
The solution of the expression (x²+y²)/x⁴ is [(1/x² + y²/x⁴)].
What is an expression?The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
The given expression is (x²+y²)/x⁴. The expression will be solved as,
E = (x²+y²)/x⁴
Separate the terms into two fractions,
E = (x²+y²)/x⁴
E = (x²/x⁴) + ( y² / x⁴)
Divide the divisible terms and solve,
E = (1/x² + y²/x⁴)
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What three consecutive numbers add up to 75?
Answer:
24,25,26
Step-by-step explanation:
Answer:24, 25, 26
Step-by-step explanation:
Divide the 75 by 3 because that is how many numbers you need. Then subtract 1 to get 24, add 1 to get 26, and also use 25.
What is the y intercept of the line y + 11=-2(x+1.5)
[tex]y +11 = -2(x+1.5)\\\\\implies y = -2x -3 -11\\\\\implies y = -2x - 14\\\\\text{The above equation is in a form of y = mx +b,}~\text{where}~~ b = -14~\text{ is the y-intercept.}[/tex]
CD is a line parallel to AB and passes through the point (3, 5).
c. Find the equation of the line CD
Answer:
y=5/3x+b
Step-by-step explanation:
Supposing CD uses the equation y=mb (meaning CD passes through the origin) and passes through (3,5), we then know the slope if 5/3 and the y intercept is 0. We can then write CD's equation as y=5/3x+0, or just y=5/3x.
So if AB is parallel to CB, then their equation is y=5/3x+b, as we don't the y-intercept yet.
Thank you!
What is the value of X?
Answer: It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable
The base of a triangle is v245 cm and its height is V20 cm. Find its area.
The given information of the base length and the height of the
rectangle are sufficient to find the area of the triangle.
Correct response:
The area of the triangle is 35 cm.²Methods used for finding the areaGiven that the parameters are;
The base of the triangle = [tex]\sqrt{245}[/tex] cm
The height of the triangle = [tex]\mathbf{\sqrt{20}}[/tex] cm
Required:
To find the area of the triangle
Solution:
[tex]Area \ of \ a \ triangle = \mathbf{ \dfrac{1}{2} \times base \times height}[/tex]Therefore, the area, A, of the given triangle is given as follows;
[tex]A = \dfrac{1}{2} \times \sqrt{245} \ cm \times \sqrt{20} \ cm= \dfrac{1}{2} \times \sqrt{4,900} \ cm^2= \dfrac{1}{2} \times 70 \ cm^2 = 35 \ cm^2[/tex]
The area of the triangle, A = 35 cm²Learn more about the area of plane shapes here:
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I need some help with this.
I only solved #53 , it is inverse.
Which one cuz they are in different order.!!!
Answer:
wot
Step-by-step explanation:
PLEASE HELP ME (third times the charm)!!!!!!!
Answer:
the first option i think
The expression 3r - 6 can be written as _____. 3(r - 2) 3(r - 6) 3(3r - 6).
Answer:
The expression 3r - 6 can be written as 3(r - 2)
Step-by-step explanation:
We know that 3r-6=3(r-2) because 3*r is the same as 3r and we know that 3*-2 is -6 hence making them equal. And to check it we know that 3r-6 is equal to 3r-6.
Will mark brainly!! :)
What is the inverse of [tex]f(x)=-2x+7\\[/tex]
[tex]f^{-1} (x) =2x-\frac{7}{2}[/tex]
[tex]f^{-1} (x)=-2x+7[/tex]
[tex]f^{-1} (x)=\frac{1}{2}x-\frac{7}{2}[/tex]
[tex]f^{-1} (x)=-\frac{1}{2} x+\frac{7}{2}[/tex]
Answer:
[tex] {f}^{ - 1} (x) = - \frac{1}{2} x + \frac{7}{2} [/tex]
What is the LCD of 1/5 and 9/7