Question

只有几题，悬赏20分

0.8乘【13-（3.12+5.28）】用合适方法计算
0.64乘2.5成1.25
2.73乘1.82+9.18乘2.73-2.73
2.5+3.91除（22-19.7）

Answer 1

0.8×[13-(3.12+5.28)]
= 0.8×[13-8.4]
= 0.8×4.6
= 3.68

0.64×2.5×1.25
= 0.8×0.8×2.5×1.25
= (0.8×2.5)×(0.8×1.25)
= 2×1
= 2

2.73×1.82+9.18×2.73-2.73
= 2.73×(1.82+9.18-1)
= 2.73×（11-1)
= 2.73×10
= 27.3

2.5+3.91÷（22-19.7）
= 2.5 + 3.91÷2.3
= 2.5 + 1.7
= 4.2

Answer 2

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