已知边长为x,y的长方形的周长为44,面积为64,5x²y+5xy²-10xy的值.

问题描述:

已知边长为x,y的长方形的周长为44,面积为64,5x²y+5xy²-10xy的值.

x+y=44÷2 =22
xy=64
5x²y+5xy²-10xy
=5xy(x+y-10)
=5×64×﹙22-10)
=3840