-2y(y-3)=-3(6-2)y
1.5y+8y-6y=2y-3
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
(y^2-3y+2)(y^2+3y-2)=y^2(y+3)(y-3)
解3y+5/3y-6=1/2+5y-4/2y-4
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
4x-2y-6y*-y-3x+5y* *=2 就是平方
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
解方程:(y+4)/5+y+6=(y+8)/2-(y+4)/3
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于