Step by step
The question
Question: solve 2y/5 − 1 = 3.
1 Remove the fraction
The bottom number is 5.
Times 5 will remove it.
We multiply every part by 5.
We do it on both sides.
Why both sides?
The = sign means both sides are the same amount.
If we change only one side, they are not the same any more.
5 divided by 5 is 1.
Write what is left.
Do the multiplications.
No more fractions!
We want y by itself.
Two things are stuck to y: times 2 and − 5.
The − 5 is on the outside, so it comes off first.
Then the times 2.
2 Remove the − 5
To remove − 5, we add 5.
We do it on both sides, so they stay equal.
− 5 and + 5 make zero.
Cross them out.
15 + 5 = 20.
Now we have 2y = 20.
3 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, so they stay equal.
2 divided by 2 is 1.
So just y is left.
20 divided by 2 is 10.
So y = 10!
4 Check
Let's check: put 10 in place of y.
We get 3, the same as the right side.
So y = 10 is right!
Let's look back.
First: remove the fraction.
Then: remove the − 5.
Then: remove the 2.
Last: check.