设x,y满足(x-1)+(2y+1)^2=0,求-2x/y的平方根

问题描述:

设x,y满足(x-1)+(2y+1)^2=0,求-2x/y的平方根

x-1=0
x=1
2y+1=0
y=-1/2
-2x/y=4