Question

Phân tích đa thức thành nhân tử:

a) a³+a²c-abc+b²c+b³

b) x³-7x-6

c) x³-x²-14x+24

giúp mk nha! mk cần gấp! Ai nhanh, đúng mk tick. thank you!

Answer 1

a) a³+a²c-abc+b²c+b³ =(a³+b³)+(a²c-abc+b²c)=(a+b)(a²-ab+b²)+c(a²-ab+b²)=(a²-ab+b²)(a+b-c)

b) x³-7x-6 = x³+x²-x²-x-6x-6=x²(x+1)-x(x+1)-6(x+1)=(x+1)(x²-x-6)=(x+1)(x-3)(x+2)

c) x³-x²-14x+24=x³-2x²+x²-2x-12x+24=x²(x-2)+x(x-2)-12(x-2)=(x-2)(x²+x-12)=(x-2)(x+4)(x-3)

Answer 2

Thank bn. 

Answer 3

\(x^3-7x-6\)

\(=x^3+x^2-x^2-x-6x-6\)

\(=x^2\left(x+1\right)-x\left(x+1\right)-6\left(x+1\right)\)

\(=\left(x+1\right)\left(x^2-x-6\right)\)

\(=\left(x+1\right)\left(x+2\right)\left(x-3\right)\)