已知:x+y=12,xy=9,则x²y+2xy²分之x²+3xy+2y²=
问题描述:
已知:x+y=12,xy=9,则x²y+2xy²分之x²+3xy+2y²=
答
x²y+2xy²分之x²+3xy+2y²=
=(x+2y)(x+y)/xy(x+2y)
=(x+y)/xy
=12/9
=4/3