x²-12xy+36y²=0,则x-5y/x+5y

问题描述:

x²-12xy+36y²=0,则x-5y/x+5y
A. 1/11B.1/yC. 11 D. y/11

x²-12xy+36y²=0
(x-6y)²=0
x=6y
(x-5y)/(x+5y)
=(6y-5y)/(6y+5y)
=1/11
所以选 A