Question

13/21×17+8÷21/17 简便运算, 我看过好多了,都不怎么样

Answer 1

13/21×17+8÷21/17
=(13/21)×17+8X(17/21)
=(17/21)X13+8X(17/21)
=(17/21)X(13+8)
=(17/21)X21
=17
或
13/21×17+8÷21/17
=221/21+136/21
=17
或
13/21×17+8÷21/17
[(13+8)*17]/21
=21*17/21
=17

Answer 2

=17/21×12+8×17/21
=17/21×（12+8)
=17/21×(21-1)
=17/21×21-17/21×1
=17-17/21
=16+4/21
=16又4/21

Answer 3

13/21×17+8÷21/17
=17/21X13+8X17/21
=(13+8)X17/21
=21X17/21
=17

Answer 4

[(13+8)*17]/21=21*17/21=17

Answer 5

13/21×17+8÷21/17
=13/21×17+8×17/21
= 13/21×17+17×8/21
=17×（13/21+8/21）
=17×1
=17