38.2-7.08-20.7-2.22用简便方法计算
问题描述：
38.2-7.08-20.7-2.22用简便方法计算
还有这种题型17.87-（3.91
7.87）用简便方法计算
答
38.2-7.08-20.7-2.22
=38.2-(7.08+2.22+20.7)
=38.2-(9.3+20.7)
=38.2-30
=8.2
17.87-（3.91+7.87）
=17.87-7.87-3.91
=17-3.91
=13.09