解:11/23-9/17等于( -20/391 )
∵已知需求出11/23-9/17等于多少
X - Y = Z
∴11/23 - 9/17
= (11×17)/(23×17)- (9×23)/(17×23)
= 187/391 - 207/391
= (187-207)/391
= -20/391
答:11/23-9/17等于-20/391
分数计算
11/23-9/17
=187/391-207/391
=-20/391