3(x+2) = 2(2x+7)
3x + 6 = 4x + 14 (On the left side we distribute 3 through parenthesis and on the right side we do the same with 2)
3x - 4x = 14 - 6 (Here we move 4x from the right to the left side and it changes its sign. We do the same with 6)
-x = 8
x = - 8