\(x^2+2xy+y^2-xz-yz\)
\(=\left(x+y\right)^2-z\left(x+y\right)\)
\(=\left(x+y\right)\left(x+y-z\right)\)
mk chỉnh lại đề
\(x^2-2xy+y^2-z^2+2zt+t^2\)
\(=\left(x-y\right)^2-\left(z-t\right)^2\)
\(=\left(x-y-z+t\right)\left(x-y+z-t\right)\)
mk chỉnh lại đề:
\(ax^2+cx^2-ay+ay^2-cy+cy^2\)
\(=x^2\left(a+c\right)-y\left(a+c\right)+y^2\left(a+c\right)\)
\(=\left(a+c\right)\left(x^2-y+y^2\right)\)
\(ax^2+ay^2-bx^2-by^2+b-a\)
\(=x^2\left(a-b\right)+y^2\left(a-b\right)-\left(a-b\right)\)
\(=\left(a-b\right)\left(x^2+y^2-1\right)\)
\(ac^2-ad-bc^2+cd+bd-c^3\)
\(=a\left(c^2-d\right)-b\left(c^2-d\right)-c\left(c^2-d\right)\)
\(=\left(c^2-d\right)\left(a-b-c\right)\)
