1. (2022一下·惠东期中) 细心算一算

12-7=        14-6=          8+5=         11-4=

18-9=        4+9=           16-7=        14-7=

13-6=        15-8=          11-5=        9+5=

11-2=        12-3=          13-4=        16-9=