5+70= 49-7= 20-5= 84-4=
59-30= 66+9= 38-9= 27-3=
12-5= 34+7= 54-5= 17+6=
21-5+8= 71-40-20= 90-(13+7)=
37+(9-3)= 52+30+7= 56-(10-4)=
微信扫码预览、分享更方便