∴x:y=y:x2,怎么解得x:y= 2:1 x:y=y:x^2 怎么会解得x:y= 2:1的?
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
解方程组4x+y=53x-2y=1得x=1y=1,把
十万分,[3x+2y]/2=[2x+y]/3=[x-y+1]/4 解得.
已知实数x,y 满足x2+y2+2x=0则x+y得最小值
已知[(x2+y2)-(x-y)2+2y(x-y)]÷4y=1,求4x/4x2-4y2-1/2x+y的值,
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知4x=9y求(1)x+y/y (2)y-x/2x
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
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
已知X 、Y为实数,Y=根下{(X2-4)+根下(4-X2)+1}除以x-2,求3X+4Y得值