Question

5.8✘2.9+55.8✘7.1用简便方法算？

Answer 1

解:可以先将55.8运用拆分法分解为(50+5.8)分别乘以7.1，然后将相同因数运用提取公因式法提取5.8，按四则运算法则进行计算。计算过程
5.8x2.9+55.8x7.1
=5.8x2.9+(5.8+50)ⅹ7.1
=5.8ⅹ2.9+5.8x7.1+50ⅹ7.1
=5.8x(2.9+7.1)+50ⅹ7.1
=5.8ⅹ10+50x7.1
=58+355
=413。

Answer 2

5.8x2.9+55.8x7.1用简便方法算？
55.8应该是5.8
5.8x2.9+5.8x7.1
=5.8x(2.9+7.1)
=5.8x10
=58

Answer 3

5.8*2.9+55.8*7.1
=5.8*2.9+55.8*（10-2.9）
=5.8*2.9+558-55.8*2.9
=55.8-50*2.9
=558-145
=413