Step by step
The question
Question: solve (x + 2)/4 = 3/2.
Two fractions are equal.
1 Cross multiply
When two fractions are equal, we can cross multiply.
These two are equal.
Work out the multiplications.
2 Remove the 2
The 2 multiplies the whole bracket.
Easy way: remove the 2 first.
To remove times 2, we divide by 2.
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.
2 divided by 2 is 1.
So just the bracket is left.
12 divided by 2 is 6.
Now we have x + 2 = 6.
We don't need the bracket any more.
3 Remove the + 2
We want x by itself.
The + 2 is in the way.
To remove + 2, we take away 2.
We do it on both sides, so they stay equal.
+ 2 and − 2 make zero.
Cross them out.
6 − 2 = 4.
So x = 4!
4 Check
Let's check: put 4 in place of x.
First the left side.
Now the right side.
Both sides are 3/2.
So x = 4 is right!
Let's look back.
First: cross multiply.
Then: remove the 2.
Then: remove the + 2.
Last: check.