In these equations;

10+x=15 subtract 10 to both sides

and

x-32=20 add 32 to both sides

how do you know when you are supposed to add or subtract a number to both sides of an equation?

When dealing with these types of equations the main goal is to find x. In order to find x you must get x by itself.

In the example 10+x=15 you subtract 10 on both sides so that way x is by itself

10+x=15

x=15-10

x=5

In the other equation x-32=20 you have to add 32 to both ways in order to get x by itself

x-32=20

x=20+32

x=52

- you subtract the number from both sides when it is positive

- you add the number to both sides when it is negative

- when you + / - the same number with two different signs they will cancel out

ex:

-23+23=0

-5+5=0