jika f(x) dibagi (x+1) sisa nya 4 dan dibagi (x-2) sisanya -2 kalau f(x) dibagi (x2-x-2) memberi sisa

sisa = f(x) = ax + b

x + 1 = 0 ---> x = -1
f(-1) = 4
-a + b = 4 ... (1)

x - 2 = 0 ---> x = 2
f(2) = -2
2a + b = -2 ... (2)

Eliminasi Substitusi persamaan (1) dan (2)
a = -2
b = 2

f(x) dibagi (x² - x - 2)
x² - x - 2 = (x + 1)(x - 2)

Sisa = f(x) = ax + b = -2x + 2 ✓