题目内容
要求写出必要的解题过程
(1)5.35×0.25+2.65×
(2)[(1-
)(1-
)(1-
)]÷(0.1+0.2+0.3)
(3)9
+99
+999
+3×
(4)解方程:3x-0.8×75%=2.1.
(1)5.35×0.25+2.65×
1 |
4 |
(2)[(1-
1 |
2 |
1 |
3 |
1 |
4 |
(3)9
9 |
10 |
9 |
10 |
9 |
10 |
1 |
10 |
(4)解方程:3x-0.8×75%=2.1.
(1)5.35×0.25+2.65×
1 |
4 |
=5.35×0.25+2.65×0.25,
=(5.35+2.65)×0.25,
=8×0.25,
=2;
(2)[(1-
1 |
2 |
1 |
3 |
1 |
4 |
=[
1 |
2 |
2 |
3 |
3 |
4 |
=
1 |
4 |
=
5 |
12 |
(3)9
9 |
10 |
9 |
10 |
9 |
10 |
1 |
10 |
=9.9+99.9+999.9+(0.1+0.1+0.1),
=(9.9+0.1)+(99.9+0.1)+(999.9+0.1),
=10+100+1000,
=1110;
(4)3x-0.8×75%=2.1,
3x-0.6=2.1,
3x-0.6+0.6=2.1+0.6,
3x=2.7,
3x÷3=2.7÷3,
x=0.9.
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