(0.7X+0.6Y)/(X+Y)=0.66(X+Y);【0.7(x-5)+0.6(Y-5)】/(X+Y-10)=0.6
分式的加减:[(x/y-y/x)除以(x+y)+x(1/y-1/x)]除以1+x/y,其中x=5,y=2
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)
若3x-5y=0,则x+y/x=(),x-y/y=(),2x-3y/2x+3y=( )
.先化简再求值:(2x+y)(2x+y)-(2x-y)平方其中X,Y满足X平方+Y平方-2X+4Y+5=0
因式分解 -5x³y(x-y)³+20y【x²(y-x)】²
2.(x+y)²(x-y)²-(x-y)(x+y)(x²+y²)
(x+y/4)+(x-y/5)=3
已知5x=7y,x与y( )
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
2(x-y)+3(x+y)2-5(x-y)-8(x+y)2-(x-y)
5x-4y=0,(x、y不为0),x和y( )
x+y=3,x²+y²=5,求(x-y)^2014