Tentukan a dan b jika f (x) = 2x³+5x²+ax+b dibagi x+1 sisanya 1 sedangkan jika dibagi x-2 sisanya 43

f(x) = 2x³ + 5x² + ax + b

dibagi (x + 1) sisa 1
x + 1 = 0 ---> x = -1
f(-1) = 1
2(-1)³ + 5(-1)² + a(-1) + b = 1
-a + b = -2 ... (1)

dibagi (x - 2) sisa 43
prosesnya sm spt diatas
f(2) = 43
2a + b = 7 ... (2)

Kurangkan persamaan (1) dan (2)
(1) - (2)
-3a = -2 - 7
a = -9/-3
a = 3

-a + b = -2
b = -2 - (-3)
b = 1

▶
a = 3 dan b = 1