{2x=y x/60+y/100=2.2
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
y'-2y=(e^x)-x
y'+2y/x=x通解
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
数学题已知p=x^/x-y-y^/x-y,q=(x+y)^-2Y(X+Y),
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
3(x+y)+2(x-y)=20 0.3x+0.6y=60 x=?y=?
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5