Simplify 9 - 7x - 7x to 2 - 14x
2 - 14x = 4
Subtract 2 from both sides
-14x = 4 - 2
Simplify 4 - 2 to 2
-14x = 2
Divide both sides by -14
x = -2/14
Simplify 2/14 to 1/7
x = -1/7
