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3 years ago

Factor the expression 5x^2 -22x -15

Mathematics

1 answer:

Murljashka [212]3 years ago

3 0

$5x^2-22x-15=5x^2\underbrace{-25x+3x}_{-22x}-15\\\\=(5x^2-25x)+(3x-15)=5x(x-5)+3(x-5)\\\\=\boxed{(x-5)(5x+3)}$

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A storage unit is in the shape of a cube with 8-foot edge lengths.

Margaret [11]

The answer is 3,072.
Heres how I got it:

SA of a CUBE: s^3 * 6

Lets plug in our numbers-
8 * 8 * 8= 512 * 6

512 * 6= 3072

7 0

3 years ago

you have $20 to spend at the snack bar all the snacks at the snack bar cost $1.25 how much money will you have left if you buy 1

Dominik [7]

You will have $5 left because if you spend 1.25 on 12 snacks you will spend $15

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3 years ago

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Write a cubic function whose graph goes through the points: (-5, 0) (1, 0) (2, -2) (4, 0)

Free_Kalibri [48]

Answer:

f(x) = $\frac{1}{7}(x+5)(x-1)(x-4)$

Step-by-step explanation:

Let the equation of the give cubic function is,

f(x) = p(x - a)(x - b)(x - c)

Here, a, b, c and d are the x-intercepts of the given graph.

Since, x-intercepts given in the graph are x = -5, 1 and 4,

Equation of the curve will be,

f(x) = p(x + 5)(x - 1)(x - 4)

Since, the graph of this function passes through (2, -2) also

-2 = p(2 + 5)(2 - 1)(2 - 4)

-2 = -p(14)

p = $\frac{2}{14}$

p = $\frac{1}{7}$

Therefore, equation will be,

f(x) = $\frac{1}{7}(x+5)(x-1)(x-4)$

5 0

3 years ago

A college job placement office collected data about students’ GPAs and the salaries they earned in their first jobs after gradua

frez [133]

Answer:

X is the GPA

Y is the Salary

Standard deviation of X is 0.4

Standard deviation of Y is 8500

E(X)=2.9

E(Y)=47200

We are given that The correlation between the two variables was r = 0.72

a) $y = a+bx$

$b = \frac{\sum(x_i-\bar{x})(y_i-\bar{y})}{\sum(x_i-\bar{x})^2} = \frac{r \times \sqrt{var(X) \times Var(Y)}}{Var(X)} = \frac{0.72 \times \sqrt{0.4^2 \times 8500^2}}{0.4^2} = 15300$

$a=y-bx = 47200-(15300 \times 29) = 2830$

So, slope = 15300

Intercept = 2830

So, equation : $y = 2830+15300x$

b) Your brother just graduated from that college with a GPA of 3.30. He tells you that based on this model the residual for his pay is -$1880. What salary is he earning?

$y = 2830+15300 \times 3.3 = 53320$

Observed salary = Residual + predicted = -1860+53320 = 51440

c)) What proportion of the variation in salaries is explained by variation in GPA?

The proportion of the variation in salaries is explained by variation in GPA = $r^2 = (0.72)^2 =0.5184$

8 0

3 years ago

a beverage is made by mixing 3 parts of water with 5 parts of fruit juice how many parts of water are mixed with 1 part on fruit

Fittoniya [83]

Answer:

$\frac{3}{5}=0.6$

Step-by-step explanation:

Given the initial ratio of 3 parts water to 5 parts fruit juice, you can set up a proportion (equivalent ratios) to determine the amount of water needed with just 1 part of fruit juice:

$\frac{water}{fruit}=\frac{3}{5}=\frac{x}{1}$

cross multiply: 5x = 3

divide: 5x/5 = 3/5 or x = 3/5

3/5 = 0.6 parts water

7 0

3 years ago

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