Question

ax+ay+x²-y²

x²-xy+2y-4

x²-2ax-4ay-y²

^{giai nhanh giup em nha}

 

Answer 1

\(1,=a\left(x+y\right)+\left(x-y\right)\left(x+y\right)=\left(a+x-y\right)\left(x+y\right)\\ 2,=\left(x-2\right)\left(x+2\right)-y\left(x-2\right)=\left(x+2-y\right)\left(x-2\right)\\ 3,Sửa:x^2-2ax-2ay-y^2\\ =\left(x-y\right)\left(x+y\right)-2a\left(x+y\right)=\left(x-y-2a\right)\left(x+y\right)\)

Answer 2

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

b)\(x^2-xy+2y-4=\left(x^2-4\right)-\left(xy-2y\right)=\left(x-2\right)\left(x+2\right)-y\left(x-2\right)=\left(x-2\right)\left(x+2-y\right)\)

c)\(x^2-2ax-4ay-y^2=\left(x^2-y^2\right)-\left(2ax+4ay\right)=\left(x-y\right)\left(x+y\right)-2a\left(x+y\right)=\left(x+y\right)\left(x-y-2a\right)\)