问题
解答题
脱式计算 5×
12×(
|
答案
(1)5×
×1 3
×2 5 3 10
=(5×
)×(2 5
×1 3
)3 10
=2×1 10
=
;1 5
(2)12×(
+1 4
-1 3
)1 6
=12×
+12×1 4
-12×1 3 1 6
=3+4-2
=5;
(3)
÷[1÷(5 7
-2 3
)]1 5
=
÷[1÷5 7
]7 15
=
÷5 7 15 7
=
×5 7 7 15
=
.1 3