(2/5y-0.5x)(0.5y+2/5y)
数学(x-y)^5*(y-x)^3*(x-y)^2
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
(X+2Y)(5X-2Y)
(2X-3y)-(5x-y)
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [(x+y)(x-y)-(x-y)^2+2y(x-y
x-y / 5y= (y-x)^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
5(x+y-2)=3-y
[(x+2y)^2 -(x+y)(3x-y)-5y^2]÷2x
2(2x+3y)(3x+2y)-(6x-y)(2x-5y)
化简:[(x+2y)^2-(x+y)(3x-y)-5y^2]/2x