能简算的要简算.7/9÷13/5+2/9×5/13

问题描述:

能简算的要简算.7/9÷13/5+2/9×5/13

7/9÷13/5+2/9×5/13
=7/9× 5/13+2/9×5/13
=(7/9+2/9)×5/13
=1×5/13
=5/13