8x^3+42x^2+mx-5 dibagi 4x-1 hasil a =?
Matematika
imchae
Pertanyaan
8x^3+42x^2+mx-5 dibagi 4x-1 hasil a =?
1 Jawaban
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1. Jawaban whongaliem
f (x) dibagi ax - b ⇒ sisa = f (b/a)
habis dibagi ⇒ sisa = 0
sisa = f (1/4)
0 = 8 (1/4)³ + 42 (1/4)² + m (1/4) - 5
0 = 8 (1/64) + (42/16) + m/4 - 5
0 = (1/8) + 21/8 + m/4 - 5 ..... kalikan dengan 8
0 = 1 + 21 + 2m - 40
0 = - 18 + 2m
2m = 18
m = 18/2
m = 9