I have already put this equation into the calculator and got the answer 5, but I do not know how to solve it.

159= -x -4(-7x -6)   distribute the -4 across both terms in the parentheses..we have

159 =-x +28x +24   subtract 24 from both sides and simplify

135 = 27x    divide by 27 on both sides

5 = x