Question

求这道数学题如何做？ 要求简便啊、

（3.75-2.9+2.25）除以 百分之31

Answer 1

（3.75+2.25-2.9）/31%
=（6-2.9）/31%
=3.1/0.31
=10

Answer 2

(3.75-2.9+2.25)/31%
=[(3.75+2.25)-2.9}/31%
=3.1/0.31
=10

Answer 3

[(3.75+2.25)-2.9]/0.31=3.1/0.31=10