Question

我好着急，请你帮帮我这几题吧！

3200÷4÷5等于多少？怎样简便运算99×38+38等于多少？怎样简便运算72×125等于多少？怎样简便运算17×23-23×7等于多少？怎样简便运算？

Answer 1

3200÷4÷5
=800÷5
=160

99×38+38
=99×38+38×1
=（99+1）×38
=100×38
=3800

72×125
=（80-8）×125
=80×125-8×125
=10000-1000

=9000

17×23-23×7
=（17-7）×23
=10×23
=230

Answer 2

3200÷4÷5
=800÷5
=160
99×38+38
=99×38+38×1
=（99+1）×38
=100×38
=3800
72×125
=（80-8）×125
=10000-1000
=9000
17×23-23×7
=（17-7）×23
=10×23
=230