⇔ (3xy + 3y² + 6y) + (x² + 2x + xy) ⇔ 3y(y + x + 2) + x(x + y + 2) ⇔ (x + 3y) + (x + 2 + y) * Đúng hok ta ???? * Bình luận
`x^2+4xy+2x+3y^2+6y`
`⇔2x+6y+3y^2+xy+3xy+x^2`
`⇔2(x+3y)+y(3y+x)+x(3y+x)`
`⇔(2+x+y)(x+3y)`
⇔ (3xy + 3y² + 6y) + (x² + 2x + xy)
⇔ 3y(y + x + 2) + x(x + y + 2)
⇔ (x + 3y) + (x + 2 + y)
* Đúng hok ta ???? *