<span>-8xy+4y-4x-3y+2x+8xy = у-2х = 10,3+8,8 = 19,1
</span>
<span>8у -4у-12= -50
4у= -50+12
4у= -38
у= -38:4
у= -9.5</span>
1)=(x-y)(a-b);
2)=(a+b)(3x-4y);
3)=3x(m-2n)-4y(m-2n)=(3x-4y);
4)=3a(x-y)-(x-y)=(3a-1)(x-y);
5)=(y-3)(y-3)-4(y-3)= (y-3)(y-3-4)=(y-3)(y-7);
6)= (x+2)(3y-1+2y-7)=(x+2)(5y-8)