go to WWW. HelpTeacher.com. Type in the type of math you are doing, and it should pull up some examples to help you with that. Hopefully it will.
Yes you always do.
eg x - 2 = 8
x - 2 + 2 = 8 + 2
x = 10
if we plug x = 10 into the original equation we se that this fits:-
10 - 2 = 8
The answer to the question is c