Math Homework Question?

Question

1/2y = -3/4y - 40. I know the answer to this is -32, but I need to know how to get to that answer. What are the steps?

Answer 1

First, you can make the problem simpler by eliminating the fractions.  To do that, multiply both sides by 4.

This gives you 2y = -3y - 160.

Then combine the terms (get all the y's one side).  To do that, add 3y to both sides.

This gives you 5y = -160.

Then divide both sides by 5.

This gives you y = -32, which is your final answer.

Answer 2

It's been 30 years since I was at school but here goes...

1/2y = -3/4y - 40

add 3/4y to both sides to get rid of the -3/4y on the right so

1/2y + 3/4y = -40

add the Y's using their common denominator so

2/4y (which is the same as 1/2y) + 3/4y = -40

5/4y = -40

multiply both sides by 4/5 to get rid of the 5/4 on the left so

y = 4/5(-40)

y = (4 x -40)/5

y = -160/5

y = -32