Jika f(x) = ax + b dan (f ° f) (x) = 16x - 15, maka nilai a + b =

f(x) = ax + bfof(x) = f{ f(x)} = f(ax+b) = 16x -15a(ax+b)+b = 16x - 15a²x + ab + b = 16x - 15a² = 16 --> a = 4 atau a = - 4.ab+b = -15b(a+1) = -15b = -15/(a+1)untuk a = 4 ---> b= -15/(4+1) = - 3untuk a = -4 --> b = -15/(-4+1)= 5
nilai a + b =...a= 4, b = - 3 ---> a + b = 4- 3 = 1a= -4, b = -5 --> a + b = -4 - 5 = - 9.(a+b)= (1, -9)