Question

Diketahui f(x)= x²-4x+5, g(x) = x-2 dan h(x)= 2x+3.Jika (f o g o h) (x) =10, maka nilai x=..

Answer 1

(f o g)(2x + 3) = 10
f((2x + 3) - 2) = 10
(2x + 1)² - 4(2x + 1) + 5 = 10
4x² + 4x + 1 - 8x - 4 - 5 = 0
4x² - 4x - 8 = 0
x² - x - 2 = 0
(x + 1)(x - 2) = 0
x = -1 atau x = 2

Answer 2

(f o g)(2x + 3) = 10
f((2x + 3) - 2) = 10 (2x + 1)² - 4(2x + 1) + 5 = 10 4x² + 4x + 1 - 8x - 4 - 5 = 0
4x² - 4x - 8 = 0 x² - x - 2 = 0 (x + 1)(x - 2) = 0
x = -1 = x = 2