3.5×9.9+3.5的简便运算

问题描述:

3.5×9.9+3.5的简便运算

3.5×9.9+3.5
=3.5*(10-0.1)+3.5
=3.5*10-3.5*0.1+3.5
=35+3.5-0.35
=38.5-0.35
=38.15