4/9*5/11+5/9*7/11如何简算?

题目

4/9*5/11+5/9*7/11如何简算?

答案

4/9*5/11+5/9*7/11
=4/9x5/11+7/9x5/11
=(4/9+7/9)x5/11
=11/9x5/11
=5/9
不懂的欢迎追问...