diketahui 3x^3 - 4x^2 - 13x - 5 ≡ (ax+b) (x-3) (x+1) + c. nilai a - 2(b+c)
Matematika
amel421
Pertanyaan
diketahui 3x^3 - 4x^2 - 13x - 5 ≡ (ax+b) (x-3) (x+1) + c. nilai a - 2(b+c)
1 Jawaban
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1. Jawaban 123WS
[tex]3x^3 - 4x^2 - 13x -5 = (ax+b)(x-3)(x+1) + c \\ \\ 3x^3 - 4x^2 - 13x -5 = (ax^2 +(b-3a)x -3b) (x+1) + c \\ 3x^3 - 4x^2 - 13x -5 = ax^3 + (b-2a)x^2 -(2b+3a)x - 3b + c \\ \\ a=3; \\ \\ b-2a-2b-3a = -17 \\ -b-5(3) = -17 \\ b=17-15\\ b=2;\\\\ -3b+c= - 5\\ -3(2)+c= -5\\ c=1 [/tex]