Question

[tri dung Le]

phân tích đa thức ->nhân tử:

a)2x²+4x-70

b)x³-5x²+8x-4

c)x^2-10+16

^{rút gọn:}

(8x-8x³-10x²+3x⁴-5):(3x²-2x+1)

Answer 1

[Thắng Nguyễn]

Bài 1:

a)2x²+4x-70

=2(x²+2x-35)

=2(x²+7x-5x-35)

=2[x(x+7)-5(x+7)]

=2(x-5)(x+7)

b)x³-5x²+8x-4

=x³-4x²+4x-x²+4x-4

=x(x²-4x+4)-(x²-4x+4)

=(x²-4x+4)(x-1)

=(x-2)²(x-1)

c)x²-10x+16

=x²-2x-8x+16

=x(x-2)-8(x-2)

=(x-8)(x-2)

Bài 2:

\(\frac{8x-8x^3-10x^2+3x^4-5}{3x^2-2x+1}=\frac{\left(x^2-2x-5\right)\left(3x^2-2x+1\right)}{3x^2-2x+1}=x^2-2x-5\)

Answer 2

[tri dung Le]

bài 2 ghi rõ tí  ko hỉu mấy