5x(6x+3y)+3y(2x-4y)-6x(5y-2x)
30x^2+15xy+6xy-12y^2-30xy+12x^2
42x^2-12y^2-9xy
4y-2(y-3)-3(y-3(4-2y)+8)
4y-2y-6-3(y-12+6y+8)
4y-2y-6-3y+36-18y-24
-23y+6
42х^2-12у^2-9ху
-23у+6
5x(6x+3y)+3y(2x-4y)-6x(5y-2x)
30x^2+15xy+6xy-12y^2-30xy+12x^2
42x^2-12y^2-9xy
4y-2(y-3)-3(y-3(4-2y)+8)
4y-2y-6-3(y-12+6y+8)
4y-2y-6-3y+36-18y-24
-23y+6
42х^2-12у^2-9ху
-23у+6