Question

phân tích đa thức thành nhân tử

a) \(x^2+2x-3\)

b)\(2x^2+6x-x-3\)

Answer 1

\(x^2+2x-3\)

\(=x^2-x+3x-3\)

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

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

\(2x^2+6x-x-3\)

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

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

Answer 2

a)\(x^2+2x-3=x^2+3x-x-3\) 

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

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

Answer 3

a) x\(^2\) -       x      +        3x      -     3

= x(x -1) + 3(x -1)

=(x - 1)(x + 3)

b) = 2x \(^2\)+ 5x + 3

= 2x\(^2\)+ 2x + 3x + 3

= 2x(x + 1) + 3(x + 1)

= (2x + 3)(x + 1)