1. (2024一下·桐乡市期末) 算一算

13-7=	30+40=	62-4=	58-40=	30+8+5=
8+7=	19-8=	60+8=	23+30=	31-5-20=
45+5=	54-8=	78-4=	40+60=	12-6+8=
90-60=	6+28=	18-9=	66-7=	48-7-9=
20+46=	64-6=	6+20=	50+3=	80-(50-30)=