3 years ago

Help please!!! Will mark you brainliest

Mathematics

1 answer:

Illusion [34]3 years ago

6 0

Answer:

x=11

Step-by-step explanation:

So we know that

5x+5+2x+8=90

we combine like terms

7x+13=90

subtract both sides by 13

7x=77

divide both sides by 7

x=11

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3x + 3y =15 and x = -3y -1

saul85 [17]

Answer:

(x, y) = (8, -3)

Step-by-step explanation:

You can substitute for x in the first equation:

3(-3y -1) +3y = 15

-6y = 18 . . . . . add 3 and simplify

y = -3 . . . . . . . divide by -6

x = -3(-3) -1 = 8 . . . . find x using the second equation

The solution to this system of equations is (x, y) = (8, -3).

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3 years ago

A scientist wishes to estimate the mean breaking strength of a certain type of steel rod within 3.0 psi with 95% confidence. Bas

yaroslaw [1]

Answer:97 rods

Step-by-step explanation:

The number of steel rods for 95% confidence level

$n=\left ( \frac{Z_\frac{\alpha }{2}\times \hat{\sigma }}{E} \right )^2$

$Z_\frac{\alpha }{2}=1.96$

E=3

$\hat{\sigma }=15$

Substituting values

$n=\left ( \frac{1.96\times 15}{3}\right )^2$

$n=96.04\approx 97$

Thus 97 rods is tested

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4 years ago

Find the area of the or rectangle square. 15 in and 12in

Elza [17]

Multiply the length and the width giving you 180

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3 years ago

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A sporting goods store ordered 144 cans if tennis balls

lapo4ka [179]

I need to know the rest of the question in order to help you! :D

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ABCD is a parallelogram. Find the measure of angle C.

Svetlanka [38]

Answer:

C = 105°

Step-by-step explanation:

added in the picture

4 0

2 years ago