1.已知梯形的面积为35m²n-25mn²,高为5mn,下地长为4m,求梯形的上底长(m>n)

问题描述:

1.已知梯形的面积为35m²n-25mn²,高为5mn,下地长为4m,求梯形的上底长(m>n)

上底=2×(35m²n-25mn²)÷(5mn)-4m
=14m-5n-4m
=9m-5n