Câu hỏi của Nguyễn Thanh Hùng

Question

Bài 2 phân tích đa thức thành nhân tử

a,x^2(x-1)+16(1-x)

b,5x^2-5y^2-10x+10y

c,x^2+4x-y^2+4

Nguyễn Lê Phước Thịnh · Accepted Answer

a) Ta có: $x^2\left(x-1\right)+16\left(1-x\right)$

$=x^2\left(x-1\right)-16\left(x-1\right)$

$=\left(x-1\right)\left(x^2-16\right)$

$=\left(x-1\right)\left(x-4\right)\left(x+4\right)$

b) Ta có: $5x^2-5y^2-10x+10y$

$=5\left(x^2-y^2\right)-10\left(x-y\right)$

$=5\left(x-y\right)\left(x+y\right)-5\left(x-y\right)\cdot2$

$=5\left(x-y\right)\left(x+y-2\right)$

c) Ta có: $x^2+4x-y^2+4$

$=\left(x^2+4x+4\right)-y^2$

$=\left(x+2\right)^2-y^2$

$=\left(x+2-y\right)\left(x+2+y\right)$Câu trả lời: a) Ta có: $x^2\left(x-1\right)+16\left(1-x\right)$