Solve 3x + 2y = 12 for y

Step by step

The question

Question: solve for y in 3x + 2y = 12.

We treat the other letters like numbers.

1 Remove the 3x

We want y by itself.

The 3x is in the way.

To remove 3x, we take away 3x.

We do it on both sides.

They make zero.

Cross them out.

Now we have 2y = 12 − 3x.

2 Remove the 2

2y means 2 times y.

We want just y.

To remove times 2, we divide by 2.

We do it on both sides.

2 divided by 2 is 1.

So just y is left.

So y = (12 − 3x)/2.

3 Check

Let's check with numbers.

We pick x = 2.

Our answer gives y = 3.

Now we put all the numbers into the start.

First the left side.

Now the right side.

Both sides are 12.

So our answer is right!

Let's look back.

First: remove the 3x.

Then: remove the 2.

Last: check.