Question

Na figura ef/bc, então o valor de x é:

Answer 1

(x-1)/3 = 12/(12-3)
(x-1)/3 = 12/9
9(x-1) = 12*3
x-1 = (12*3)/9
x-1 = 12/3
x-1 = 4
x = 4+1
x = 5