Suku banyak Nomer 4 Sankyuu^^

f(x) : (x^2 - 4) => f(x) : (x + 2)(x - 2) bersisa (2x - 2)
f(-2) = 2(-2) - 2 = -6
f(2) = 2(2) - 2 = 2

f(x) : (x^2 - 9) bersisa (3x + 3) & kita misalkan hasil baginya h(x) = (ax + b)

f(x) = hasil bagi . pembagi + sisa
f(x) = (ax + b) . (x^2 - 9) + (3x + 3)

1) f(-2) = (-2a + b) (-2^2 - 9) + (3(-2) + 3)
-6 = (-2a + b) (-5) + (-3)
-3 = 10a - 5b

2) f(2) = (2a + b) (2^2 - 9) + (3(2) + 3)
2 = (2a + b)(-5) + 9
-7 = -10a - 5b

Eliminasi
10a - 5b = -3
-10a - 5b = -7
------------------- +
-10b = -10 => b = 1

10a - 5(1) = -3 => 10a = 2 => a = 1/5

Jadi
f(x) = (ax + b)(x^2 - 9) + (3x + 3)
= (1/5 x + 1)(x^2 - 9) + (3x + 3)
= 1/5 x^3 - 9/5 x + x^2 - 9 + 3x + 3
= 1/5 x^3 + x^2 + 6/5 x - 6