(1)7x-3y=54 (2)8x-3y=11 (3)1/4x-3y=8 (4)7/2x-y=3/2 y=-20 x-y
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
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
解下列方程组:(1)7x-3y=54,y=-20 (2)8x-3y=11,x-y=-8 (3)4分之1x-3y=8,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)=11,2(x-y)+5(x+y)=27
(1)﹛2x-y=5 (2) 4x-y=1 (3)5x+y=2 7x-3y=20 y=2x+3 x-3y=4 (4)3x
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=