下列各题能简算的要简算. 3.1+2.4+1.9+3.6 300-288÷24 48×(3/8+5/6) 0.46×98+0.92 4/5×2/5÷4/5×2/5 21÷(1/3+2/5)÷9/11.

问题描述:

下列各题能简算的要简算.

3.1+2.4+1.9+3.6 300-288÷24 48×(
3
8
+
5
6
0.46×98+0.92
4
5
×
2
5
÷
4
5
×
2
5
21÷(
1
3
+
2
5
)÷
9
11

(1)3.1+2.4+1.9+3.6,
=(3.1+1.9)+(2.4+3.6),
=5+6,
=11;
(2)300-288÷24,
=300-12,
=288;
(3)48×(

3
8
+
5
6
),
=48×
3
8
+48×
5
6

=18+40,
=58;
(4)0.46×98+0.92,
=0.46×(100-2)+0.92,
=0.46×100-0.46×2+0.92,
=46-0.92+0.92,
=46;
(5)
4
5
×
2
5
÷
4
5
×
2
5

=(
4
5
÷
4
5
)×(
2
5
×
2
5
),
=1×0.16,
=0.16;
(6)21÷(
1
3
+
2
5
)÷
9
11

=21÷
11
15
÷
9
11

=21÷(
11
15
×
9
11
),
=21÷
3
5

=35.