Solve the problem,3(x-7)=9. show all of your work.

3(x - 7) = 9
(3 * x) - (3 * 7) = 9
3x - 21 = 9
3x - 21 + 21 = 9 + 21
3x = 30
3x/3 = 30/3
x = 10

3(10 - 7) = 9
(3 * 10) - (3 * 7) = 9
30 - 21 = 9
9 = 9

First you would distribute. 3 times x and 3 times negative 7. Then you would add negative 21 to 9 to get 30. Then you divide 3x from 30 to get 10. 
So the answer is 10