Question

1,tìm nhân tử chung

a, 8ab³-2ab^b

b,(x²+x+4)²+8x(x²+x+4)+15x²

c, 25x²-5x-49y²-7y

d, 8x²-36x²+54x-27

e, 4x⁸+1

2,cho x là số nguyên

B=x⁴-4x³-2x+12x+9 là bình phương

Answer 1

Bài 1: 

b: \(=\left(x^2+x+4\right)^2+3x\left(x^2+x+4\right)+5x\left(x^2+x+4\right)+15x^2\)

\(=\left(x^2+x+4+3x\right)\left(x^2+x+4+5x\right)\)

\(=\left(x^2+4x+4\right)\left(x^2+6x+4\right)\)

\(=\left(x+2\right)^2\cdot\left(x^2+6x+4\right)\)

c: \(=25x^2-49y^2-\left(5x+7y\right)\)

\(=\left(5x-7y\right)\left(5x+7y\right)-\left(5x+7y\right)\)

\(=\left(5x+7y\right)\left(5x-7y-1\right)\)

d: \(8x^3-36x^2+54x-27=\left(2x-3\right)^3\)