4x-3y=12,3x+2y=12,
已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y除以2x-y
已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值
解方程组:x+y/2+x-y/3=6 4(x+y)-5(x-y)=12
3y=2x y/3=x/2 12/x=9/y y/x=?y/x=?x/y=?
若x-2y=5,则式子12-x+2y=.以知3x-4y=2x+y则x∶y=
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
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
(x+y)(x+2y)(x+3y)(x+4y)=-40
先化简,再求值:(x+2y)2-2(x-y)(x+y)+2y(x-3y),其中x=-2,y=12