Question

Phân tích đa thức thành nhân tử:

a/ \(x^2+5x+6\)

b/ \(x^2\left(1-x^2\right)-4+4x^2\)

Answer 1

a/ \(x^2+5x+6\)

\(=x^2+5x+\frac{25}{4}-\frac{1}{4}\)

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

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

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

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

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

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

Answer 2

a, x²+5x=6

= x(x+5)+6

b, x²(1-x²)-4+4x²

= x².1-x²-4+4x²

= x²(1-1-4+4)

= x².0