简便运算:1/17x4/9+5/17x1/9=1/7
问题描述:
简便运算:1/17x4/9+5/17x1/9=1/7
答
1/17x4/9+5/17x1/9
=1/17x4/9+1/17x5/9
=1/17x(4/9+5/9)
=1/17x1
=1/17