X-7 = -2

x=5

You have to isolate your variable x. So you always need to isolate down to the term that contains the variable. So you need to get rid of anything else that is there. There's a -7 there. To get rid of it, you always need to do the opposite operation. Since that's a minus 7, you need to add 7 to get rid of it. You also must do the same thing to both sides of the equation or it won't be equal anymore. So you also have to add a 7 on the right side:

x - 7 + 7 = -2 + 7

Which gets you:

x = -2 + 7
x = 5

Thank you for the kind words, hauser5!