Question

6道简便运算

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Answer 1

望采纳

Answer 2

下面是完整解题思路步骤，怎么简化步骤看你自己的。

21.84×[10.8÷(48.6+5.4)-0.2]
=21.84×[54/5÷54-0.2]
=21.84×[1/5-0.2]
=21.84×0
=0

1200-197=1200-(200-3)=1200-200+3=1000+3=1003

5/6-3/8÷3/4×7/12
=5/6-3/8×4/3×7/12
=5/6-1/2×7/12
=20/24-7/24
=13/24

3/5×3.7+5.3×3/5+0.6
=0.6×3.7+0.6×5.3+0.6×1
=0.6×(3.7+5.3+1)
=0.6×10
=6

(4/5-2/3)×15-3/4
=4/5×15-2/3×15-3/4
=12-10-3/4
=2-3/4
=5/4
=1.25

9/20÷[1/2×(2/5+4/5)]
=9/20÷[1/2×6/5]
=9/20÷3/5
=9/20×5/3
=3/4
=0.75