I believe you just have to isolate the variables like in any normal equation, take for example a similar problem;
you have to isolate the x so you would add 12 to both sides;
Then you would reverse the divide by 9, you do this by multiplying both sides by nine;
finnaly you get rid of the -2, by dividing both sides by -2;
Hope that helped just appy the same concepts to the original problem.
Im so sorry that im bothering you guys on a thread that doesnt apply to my question but i dont know how to contact you guys privately, anyways melany i was wondering if you could have a look at the problem you had helped me with a bit back,
The response you gave was well worked but the solution wasnt right (at least i dont think it was) anyways the correct anwser should be 45. Think you could help me