Question

If 4x+4:9x-10 is the triplicate ratio of 4:5 find x

Answer 1

4x+4:9x-10 =4^3:5^3
(4x +4)/(9x -10) =64/125
4(x+1)125=64(9x -10)
(x+1)125=16*9x -160
160+125=x(144-125)
285=x(19)
x=285/19
x=15//