来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/11 15:29:29
简算
19.98×37-199.8×1.9+1998×0.82
7×13×(
(1)19.98×37-199.8×1.9+1998×0.82
=19.98×37-19.98×19+19.98×82
=19.98×(37-19+82)
=19.98×100
=1998;
(2)7×13×(
8
7-
14
13)
=7×13×
8
7-7×13×
14
13
=104-98
=6;
(3)13
4
11-(2
2
3-
7
11)
=13
4
11-2
2
3+
7
11
=13
4
11+
7
11-2
2
3
=14-2
2
3
=11
1
3.