问题
解答题
脱式计算.
1.25×32×2.5 (3.8-1.8÷2)×0.5
|
答案
(1)
×{1÷(5 9
-7 8
)}3 4
=
×{1÷(5 9
-21 24
)}18 24
=
×{1÷5 9
}1 8
=
×85 9
=4
;4 9
(2)1.25×32×2.5
=(1.25×8)×(4×25)
=10×100
=1000;
(3)(3.8-1.8÷2)×0.5
=(3.8-0.9)×0.5
=2.9×0.5
=1.45;
(4)
×9-6÷7 15 15 7
=
×9-6×7 15 7 15
=
×(9-6)7 15
=
×37 15
=7 5
=1
.2 5