3/7*2/5+4/5*2/7的简便运算

问题描述:

3/7*2/5+4/5*2/7的简便运算

3/7*2/5+4/5*2/7
=3/7*2/5+2/5*4/7
=(3/7 +4/7)*2/5
=2/5

3/7*2/5+4/5*2/7
=3/7*2/5+*2/5*4/7
=(3/7+4/7)*2/5
=2/5