下面各题怎样简便就怎样算. 48 49 ×50 51.4-8.56-1.44 108-1800÷45 [1-( 1 2

2024-12-02 15:27:16
推荐回答(1个)
回答1:

(1)
48
49
×50

=
48
49
×(49+1),
=48+
48
49

=48 48
48
49


(2)51.4-8.56-1.44,
=51.4-(8.56+1.44),
=51.4-10,
=41.4;

(3)108-1800÷45,
=108-40,
=68;

(4)[1-(
1
2
-
1
4
)]×
2
3

=[1-
1
4
2
3

=
3
4
×
2
3

=
1
2


(5)0.4×80×2.5×0.125,
=(0.4×2.5)×(80×0.125),
=1×10,
=10;

(6)(
11
15
-
9
5
÷3) ÷
7
15

=(
11
15
-
3
5
)×
15
7

=
2
15
×
15
7

=
2
7