розкласти на множники.
1) 4( x-y )^2 - 9y^2 =
2) 4( x-y )^2- 9x^2 =
3) 9(x-y)^2 - 4y^2 =
4) 9(y-x)^2 - 4x^2 =

1) $4(x-y)^2-9y^2=(2*(x-y))^2-(3y)^2==(2(x-y)-3y)*(2(x-y)+3y)=(2x-5y)(2x+y)$

2) $4( x-y )^2- 9x^2 =(2*(x-y))^2-(3x)^2==(2(x-y)-3x)(2(x-y)+3x)=(-x-2y)(5x-2y)$

3) $9(x-y)^2 - 4y^2 =(3(x-y))^2-(2y)^2==(3(x-y)-2y)(3(x-y)+2y)=(3x-5y)(3x-y)$

4) $9(y-x)^2 - 4x^2=(3(y-x))^2-(2x)^2==(3(y-x)-2x)(3(y-x)+2x)=(3y-5x)(3y-x)$