Question

Phân tích các đa thức sau thành nhân tử:

a) xy + xz + 3y + 3z

b) xy - xz + y - z

c) 15x + 15y - x\(^2\) - xy

d) x\(^2\) -xy - 10x + 10y

Answer 1

a) \(xy+xz+3y+3z=x\left(y+z\right)+3\left(y+z\right)=\left(x+3\right)\left(y+z\right)\)

b) \(xy-xz+y-z=x\left(y-z\right)+\left(y-z\right)\left(x+1\right)\left(y-z\right)\)

c) \(15x+15y-x^2-xy=15\left(x+y\right)-x\left(x+y\right)=\left(15-x\right)\left(x+y\right)\)

d) \(x^2-xy-10x+10y=x\left(x-y\right)-10\left(x-y\right)=\left(x-10\right)\left(x-y\right)\)