从+,-,×,÷,【】中选去适当的符号添在等号左边,使等式成立
问题描述：
从+,-,×,÷,【】中选去适当的符号添在等号左边,使等式成立
5 5 5 5 5 =1 5 5 5 5 5 =3 9 9 9 9 9 =3 5 5 5 5 5 =2 5 5 5 5 5 =4 9 9 9 9 9 =20
应该是9 9 9 9 9 =17
答
(5+5)÷5-5÷5＝1
(5+5)÷5+5÷5＝3
(9+9)÷9+9÷9＝3
(5+5+5-5)÷5＝2
(5+5+5+5)÷5＝4
(9+9)+(9+9)÷9=20
(9×9-9)÷9+9=17
(9÷9+9÷9)×9=18