Question

Rút gọn đa thức

a, \(a^2+2ab+b^2-2a-2b+1\)

b, \(x^3-4x^2+4x-1\)

c, \(x^3-3x^2-3x+1\)

d, \(14x^2-21xy^2+28x^2y^2\)

Answer 1

a) \(a^2+2ab+b^2-2a-2b+1=\left(a+b\right)^2-2\left(a+b\right)+1\)

\(=\left(a+b\right)\left(a+b\right)-2\left(a+b\right)+1=\left(a+b-2\right)\left(a+b\right)+1\)

b) \(x^3-4x^2+4x-1=x^3-3x^2+x-x^2+3x-1\)

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

c) \(x^3-3x^2-3x+1=x^3-4x^2+x+x^2-4x+1\)

\(=x\left(x^2-4x+1\right)+\left(x^2-4x+1\right)=\left(x+1\right)\left(x^2-4x+1\right)\)

d) câu này đề hình như sai rồi đó bn