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2 years ago

Which of the following equations shows how substitution can be used to solve the following

Mathematics

1 answer:

slega [8]2 years ago

8 0

Answer:

Step-by-step explanation:

the y= equation shows how... b/c we can just plug y into the 2nd equation and eliminate y and have one variable, x , to solve for :)

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Suppose it takes 45 hours for robot A to construct a new robot. Working together with robot B, it takes 25 hours for both robots

Len [333]

Answer:

56 hours 25 minutes

Step-by-step explanation:

Given:

Suppose it takes 45 hours for robot A to construct a new robot

It takes 25 hours for both robots to construct a new robot.

Question asked:

How long would it take robot B to construct a new robot, working alone ?

Solution:

Let the time taken by robot B to construct new robot = $x$

By robot A

It takes 45 hours to construct = 1 new robot

It takes 1 hour to construct = $\frac{1}{45} \ new\ robot$

By robot B

It takes $x$ hours to construct = 1 new robot

It takes 1 hour to construct = $\frac{1}{x}$ new robot

By working together

It takes 25 hours to construct = 1 new robot

It takes 1 hour to construct = $\frac{1}{25} \ new\ robot$

$\frac{1}{25}$ new robot is constructed in = 1 hour

New robot is constructed by both working together in 1 hour = New robot is constructed by robot A in 1 hour + New robot is constructed by robot B in 1 hour

$\frac{1}{25} =\frac{1}{45} +\frac{1}{x} \\$

Subtracting both sides by $\frac{1}{45}$

$\frac{1}{25}-\frac{1}{45} =\frac{1}{45} -\frac{1}{45}+\frac{1}{x} \\\\\frac{1}{25}-\frac{1}{45} =\frac{1}{x}\\\\ Taking\ LCM \ of \ 25\ and\ 45,\ we\ got\ 225$

$\frac{9-5}{225} =\frac{1}{x} \\ \\ \frac{4}{225} =\frac{1}{x}\\\\ By\ cross \ multiplication\\4\times x=225\\Dividing\ both\ sides\ by\ 4\\x=56.25\ hours$

Thus, robot B would take 56 hours 25 minutes to construct a new robot, working alone.

4 0

3 years ago

Read 2 more answers

Which of the following sets of angles sum to 180°? picture included, please help.

eduard

Answer:

Choice 3

Step-by-step explanation:

add 63 and 64 which gives you 127. Then you subtract 180 and 127. This gives you 53. 63+53+64=180. Know that the angle is 180 degrees too so you don't even have to do math.

8 0

3 years ago

Read 2 more answers

Someone pls help and show ur work

ale4655 [162]

Answer:

8x8=16

easy

https://youtu.be/WYNfQabLpuk

6 0

3 years ago

Classify the polynomial 2x3 + 6x2 - 4 by the number of terms.