How do you use inverse operation using variables?

All you have to do is, if it is multiplication.....

9x = 27

divide by 9 on both sides

to take the variable away 9 dived by 9 is 1 in this case its 0 because here 1 is worth nothing. and 27 divided by 9 is 3 so

x= 3

it is the same with addition or subtraction.

9+x=27

all you do here is subtract 9 on both sides so 9-9=0

and 27-9= 18

so x= 18

all you have to do is find the opposite ways

addition is opposite of subtraction

and multiplication is the opposite of division!