1.5x-2y=-1 -4.5x+7y=8
1.5x-2y=-1 -4.5x+7y=8
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
9y=3x-(x-1),4(x+y)-(2x+4)=8y
已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
2x-y=7,3x+y=8
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知4x=9y求(1)x+y/y (2)y-x/2x