用合理、灵活的方法计算下面各题.23+13÷(1?45)0.5×25×1.25×640.7×24.5+0.7×76.5-70%

2024-11-18 01:42:03
推荐回答(1个)
回答1:

(1)

2
3
+
1
3
÷(1-
4
5
),
=
2
3
+
1
3
÷
1
5

=
2
3
+
1
3
×5,
=
2
3
+
5
3

=
7
3


(2)0.5×25×1.25×64,
=0.5×25×1.25×8×4×2,
=(0.5×2)×(25×4)×(1.25×8),
=1×100×10,
=1000;

(3)0.7×24.5+0.7×76.5-70%,
=0.7×24.5+0.7×76.5-0.7,
=(24.5+76.5-1)×0.7,
=100×0.7,
=70.