Question

Expand the far left side, then multiply the second term by   (3x-4)/3x-4)   and multiply the entire equation by  ( 3x-4)^2 

  and simplify the mess to get 

          80x^2- 96-128 = 0        Quadrtaic formula then shows x = 2 as the largest x 

Much easier if you notice that this is a quadratic X^2 + X - 12= 0, where X = (4x -16)/(3x - 4).

Solve for X (= -4 or 3 ) and then for x.