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用简便方法计算.(1)7.6×27310+3.8×4525(2)1.1×42197+40.9÷5219−4.09×997.

题目详情
用简便方法计算.
(1)7.6×27
3
10
+3.8×45
2
5

(2)1.1×4
21
97
+40.9÷5
2
19
−4.09×
9
97
▼优质解答
答案和解析
(1)7.6×27
3
10
+3.8×45
2
5

=3.8×(2×27
3
10
)+3.8×45
2
5

=3.8×54
3
5
+3.8×45
2
5

=3.8×(54
3
5
+45
2
5
),
=3.8×100,
=380;
(2)1.1×4
21
97
+40.9÷5
2
19
−4.09×
9
97

=1.1×
409
97
+40.9×
19
97
-4.09×
9
97

=4.09×
110
97
+4.09×
190
97
-4.09×
9
97

=4.09×(
110
97
+
190
97
-
9
97
),
=4.09×3,
=12.27.