Explanation:
it's obviously the equation is equals to zero,
-12x + 16 = 0
-12x = -16
-12. 12
like terms cancel each other to remaining with x
thus,
x = 4/3
AND
4x - 12 = 0
4x = 12
4. 4
like terms cancel each other to remaining (make x subject of the formula) with x
thus,
x = 3