Jika f(x)=2x-3 dan (g°f)(x)=2x+1, maka g(x) adalah..

g(2x - 3) = 2x + 1
g(2x - 3) = 2x - 3 + 4
g(2x - 3) = (2x - 3) + 4
g(x) = x + 4

(g o f)(x) = 2x + 1
g( f(x) ) = 2x + 1
g(2x - 3) = 2x + 1

misal , 2x - 3 = a
2x = a + 3
x = (a + 3) / 2

maka ,
g(a) = 2(a + 3)/2 + 1
g(a) = a + 3 + 1
g(a) = a + 4
g(x) = x + 4

Maka , g(x) = x + 4