1. (2018一上·麒麟期末) 计算我最棒。

5+7=	5–4=	18–8=	8＋5＋ 2=
15–10=	6–3=	7+7=	3 + 7 + 9=
11+7 =	2+8=	19–10=	8 – 3 + 9=
8+8=	10–8=	5+10=	12 –2 + 4=
10 + 8=	11 –10=	10 –7=	9 + 10 –5=