Question

Diberikan f(x) = x^4 +2x3-7x^2+ax+b. Tentukan nilai a dan b jika f habis dibagi x^2 +2x-3?

Answer 1

X²+2x-3= (x+3)(x-1)
x=-3 atau x=1
f(-3)= (-3)⁴+2(-3)³-7(-3)²-3a+b
0= 81 -54 - 63 -3a+b
36= -3a+b pers (1)

f(1)= 1+2-7+a+b
0= -4+a+b
4= a+b pers(2)

-3a+b=36
a+b= 4
kurangkan
-4a = 32
a=-32/4
a = -8

a+b=4
-8+b=4
b=4+8
b=12