(5)8.6×2.7+3.5×1.6 (6)(0.19×5.4+2.6×0.19)×12.5 (7)9.99×2.22+3.34×3.33(8)1.2除4.2的商,再加5与6.02的积,和是多少?多简便运算

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 16:14:21

(5)8.6×2.7+3.5×1.6 (6)(0.19×5.4+2.6×0.19)×12.5 (7)9.99×2.22+3.34×3.33(8)1.2除4.2的商,再加5与6.02的积,和是多少?多简便运算
(5)8.6×2.7+3.5×1.6 (6)(0.19×5.4+2.6×0.19)×12.5 (7)9.99×2.22+3.34×3.33
(8)1.2除4.2的商,再加5与6.02的积,和是多少?
多简便运算

(5)8.6×2.7+3.5×1.6 (6)(0.19×5.4+2.6×0.19)×12.5 (7)9.99×2.22+3.34×3.33(8)1.2除4.2的商,再加5与6.02的积,和是多少?多简便运算
(5)8.6×2.7+3.5×1.6
=(10-1.4)×2.7+3.5×1.6
=10×2.7-1.4×2.7+7×0.8
=27-1.4×2.7+1.4×4
=27+1.4×(4-2.7)
=27+1.4×1.3
=27+1.82
=28.82
(6)(0.19×5.4+2.6×0.19)×12.5
=0.19×(5.4+2.6)×12.5
=0.19×(8×12.5)
=0.19×100
=19
(7)9.99×2.22+3.34×3.33
=3.33×6.66+3.34×3.33
=3.33×(6.66+3.34)
=3.33×10
=33.3
(8)1.2除4.2的商,再加5与6.02的积,和是多少?
4.2÷1.2+5×6.02
=4.2÷0.6÷2+5×6+5×0.02
=7÷2+30+0.1
=3.5+30.1
=33.6

28.82 19 33.3 33.6