神马作文网
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=
2x-y=7,3x+y=8
(7y-3x)-(8y-5x)=
已知方程组{2x+y=7,x+2y=8,则x-y=(),x+y=().
解方程组24/(x+y) +24/(x-y) = 7/3 ,8/(x+y) +18/(x-y) = 4/3
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
求x:y:z x:y=7/5:7/3,y:x=7:8
（x+2y)(x-2y)-(2y-x)(-2x-y)其中x=8,y=-8
X+Y=7(100X+Y)-(10Y+X)=(10Y+X)-(10X+Y)
[(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x=