Question

Phân tích thành nhân tử: A=\(2x^3+13x^2+13xy+2x^2y+21\left(x+y\right)\)

Answer 1

\(A=2x^3+13x^2+13xy+2x^2y+21\left(x+y\right)\)

=> \(A=2x^2\left(x+y\right)+13x\left(x+y\right)+21\left(x+y\right)\)

=> \(A=\left(x+y\right)\left(2x^2+13x+21\right)\)

=> \(A=\left(x+y\right)\left(2x^2+6x+7x+21\right)\)

=> \(A=\left(x+y\right)\left[2x\left(x+3\right)+7\left(x+3\right)\right]\)

=> \(A=\left(x+y\right)\left(2x+7\right)\left(x+3\right)\)

Answer 2

A=2x^3+13x^2+13xy+2x^2y+21(x+y)

=2x^3+2x^2y+13x^2+13xy+21(x+y)

=2x^2(x+y)+13x(x+y)+21(x+y)

=(x+y)(2x^2+13x+21)

=(x+y)(2x^2+6x+7x+21)

=(x+y)[2x(x+3)+7(x+3)]

=(x+y)(x+3)(2x+7)

Answer 3

A= \(2x^3+13x^2+13xy+2x^2y+21\left(x+y\right)\)

A=\(2x^2\left(x+y\right)+13x\left(x+y\right)+21\left(x+y\right)\)

A=\(\left(x+y\right)\left(2x^2+13x+21\right)\)

\(A=\left(x+y\right)\left(2x^2+6x+7x+21\right)\)

A=\(\left(x+y\right)\left(2x\left(x+3\right)+7\left(x+3\right)\right)\)

A=\(\left(x+y\right)\left(x+3\right)\left(2x+7\right)\)