已知X+Y=12,XY=9求(X²+3XY+2Y²)÷(X²2XY²)的值已知X+Y=12_数学解答

已知X+Y=12,XY=9求(X²+3XY+2Y²)÷(X²2XY²)的值
已知X+Y=12,XY=9求(X²+3XY+2Y²)÷(X²Y+2XY²)的值
上面打错了这个

人气：111 ℃　时间：2019-12-01 12:52:35

解答

(X²+3XY+2Y²)÷(X²Y+2XY²)
=(x+2y)(x+y)÷[xy(x+2y)]
=(x+y)/(xy)
=12/9
=4/3