Question

phân tích đa thức thành nhân tử

a) xy+xz-5x-5y

b) x+y-x²-xy

c) x²-xy-7x+7y

d) ax²+cx²-ay+ay²-cy+cy²

Answer 1

a) sửa đề nha bn: xy + xz - 5z - 5y

\(xy+xz-5z-5y\)

\(=x\left(y+z\right)-5\left(z+y\right)\)

\(=\left(x-5\right)\left(y+z\right)\)

b) \(x+y-x^2-xy\)

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

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

c) \(x^2-xy-7x+7y\)

\(=x\left(x-y\right)-7\left(x-y\right)\)

\(=\left(x-7\right)\left(x-y\right)\)

d) \(ax^2+cx^2-ay+ay^2-cy+cy^2\)

\(=ax^2+cx^2-ay-cy+ay^2+cy^2\)

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

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