脱式计算,能简算的要简算(1) 4 5 - 4 5 ÷ 2 3 × 1 2    

2025-05-01 22:47:23
推荐回答(1个)
回答1:

(1)
4
5
-
4
5
÷
2
3
×
1
2

=
4
5
-
4
5
×
3
2
×
1
2

=
4
5
-
3
5

=
1
5

(2)(
2
3
+
4
15
)×15
=
14
15
×15
=14;
(3)12.87+3.65+1.35
=12.87+(3.65+1.35)
=12.87+5
=17.87;
(4)74.6×19+19×25.4
=(74.6+25.4)×19
=100×19
=1900;
(5)【1-(
3
4
-
1
6
)】 ÷
2
3

=【1-
7
12
】×
3
2

=
5
12
×
3
2

=
5
8

(6)168.1÷(4.5×2-0.8)
=168.1÷8.2
=20.5;