数学,大家帮帮我5道递等式计算(能简则简)(1)23.56-23.56÷3.8×2.4(2)5.1×0.99(3)6.3÷4.2(4)(0.8+0.8+0.8+0.8)×0.25×1.25(5)[27.4-(8.35+5.25)×0.25]÷0.24

Question

数学,大家帮帮我
5道递等式计算(能简则简)
(1)23.56-23.56÷3.8×2.4 (2)5.1×0.99 (3)6.3÷4.2
(4)(0.8+0.8+0.8+0.8)×0.25×1.25 (5)[27.4-(8.35+5.25)×0.25]÷0.24

Answer 1

5道递等式计算(能简则简)
(1)23.56-23.56÷3.8×2.4
解,得：
==23.56-23.56*(5/19)×2.4
==23.56*[1-(5/19)×(12/5)]
==23.56*(7/19)
== 1.24*7
==8.68
(2)5.1×0.99
解,得：
==5.1*(1-0.01)
==5.1-0.051
==5.049
(3)6.3÷4.2
解,得：
==63÷42
==(7*9)/(7*6)
==3/2
==1.5
(4)(0.8+0.8+0.8+0.8)×0.25×1.25
解,得：
==0.8*4×0.25×1.25
==(0.8×1.25)*(4×0.25)
==1*1
==1
(5)[27.4-(8.35+5.25)×0.25]÷0.24
解,得：
==(27.4-13.6×0.25)÷0.24
==(27.4-3.4)÷0.24
==24/0.24
==100