Phân tích đa thức thành nhân tử:
a) 5x - 5y
= 5(x - y)
b) 3xy2 + x2y
= xy(3y + x)
c) 12x2y - 18xy2 - 30y3
= 2y(6x2 - 9xy - 15y2)
= 2y(6x2 + 6xy - 15xy - 15y2)
= 2y[6x(x + y) - 15y(x + y)]
= 2y(x + y)(6x - 15y)
= 6y(x + y)(2x - 5y)
d) -17x3y - 34x2y2 + 51xy3
= -17xy(x2 + 2xy - 3y2)
= -17xy(x2 - xy + 3xy - 3y2)
= -17xy[x(x - y) + 3y(x - y)]
= -17xy(x - y)(x + 3y)
e) x(y - 1) + 3(y - 1)
= (y - 1)(x + 3)
f) 162(x - y) - 10y(y - x)
= 162(x - y) + 10y(x - y)
= (x - y)(162 + 10y)
= (x - y)(256 + 10y)
a) Ta có: 5x-5y
=5(x-y)
b) Ta có: \(3xy^2+x^2y\)
\(=xy\left(3y+x\right)\)
c) Ta có: \(12x^2y-18xy^2-30y^3\)
\(=6y\left(2x^2-3xy-5y^2\right)\)
\(=6y\left(2x^2-5xy+2xy-5y^2\right)\)
\(=6y\left[2x\left(x+y\right)-5y\left(x+y\right)\right]\)
\(=6y\left(x+y\right)\left(2x-5y\right)\)
d) Ta có: \(-17x^3y-34x^2y^2+51xy^3\)
\(=-17xy\left(x^2+2xy-3y^2\right)\)
\(=-17xy\left(x^2+3xy-xy-3y^2\right)\)
\(=-17xy\left[x\left(x+3y\right)-y\left(x+3y\right)\right]\)
\(=-17xy\left(x+3y\right)\left(x-y\right)\)
e) Ta có: x(y-1)+3(y-1)
=(y-1)(x+3)
