Question

怎么样简便计算

Answer 1

99×42
=（100-1）×42
=100×42-42
=4200-42
=4158，

101×76-76
=（101-1）×76
=100×76
=7600

Answer 2

(1)
= 72×(24+76)
= 72×100
= 7200

(2)
= 25×40+25×8
= 1000+200
= 1200

(3)
=（△+□ )×24

2
99×42
= (100-1)×42
= 100×42-1×42
= 4200-42
= 4158

101×76-76
= （101-1）×76
= 100×76
= 7600

Answer 3

收到了吗？

Answer 4

99×42
=(100-1)×42
=100×42-1×42
=4200-42
=4158
101×76-76
=(101-1)×76
=100×76
=7600

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怎么样简便计算

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