28.71-7.29+2.29-2.71怎样简算
问题描述:
28.71-7.29+2.29-2.71怎样简算
答
(28.71-2.71)-(7.29-2.29)=26-5=21
答
(28.71-2.71)-(7.29-2.29)
答
(28.71+2.29)-(7.29+2.71)=31-10=21
答
28.71+2.29-(7.29+2.71)=21