\(=2\left(x^2-y^2\right)-6\left(x+y\right)=2\left(x-y\right)\left(x+y\right)-6\left(x+y\right)=\left(x+y\right)\left(2x-2y-6\right)\) Đảm bảo chuẩn ko cần chỉnh (•••
check mk nhá
2X2-2Y2-6X-6Y
=2(X2-Y2) +6(X-Y)
=2(X-Y)(X+Y)+3.2(X-Y)
=2(X-Y)(X+Y+3X-3Y)
=2(X-Y)(4X-2Y)
=4(X-Y)(2X-Y)
\(2x^2-2y^2-6x-6y\)
\(=\left(2x^2-6x\right)-\left(2y^2+6y\right)\)
\(=2x\left(x-3\right)-2y\left(y+3\right)\)
\(=2\left(x\left(x-3\right)-y\left(y+3\right)\right)\)
2x2-2y2-6x-6y=2(x2-y2)-6(x+y)
=2(x-y)(x+y)-6(x+y)
=2(x+y)(x-y-3)
2x2-2y2-6x-6y= 2(x2-y2) -6(x+y)=2(x+y)(x-y)-6(x+y)
=(x+y)(2(x-y)-6)=(x+y)(2x-2y-6)
=2(x+y)(x-y-3)
