Respuesta :
not entirely sure about the equation, but hes 4. 4 plus 11 is 15, fifteen plus 5 is 20. (fifteen is five less than 20) and 20 is 5 times his age, which is 4
x + 11 = 5x -5
x-x+11=5x-x-5
11 = 4x -5
11+5 = 4x -5+5
16 = 4x
16/4 = 4x/4
x = 4
x-x+11=5x-x-5
11 = 4x -5
11+5 = 4x -5+5
16 = 4x
16/4 = 4x/4
x = 4