12-(     )=11

11-(     )=4

17-(     )=10

15-(     )=1

(     )-1=16

19-(     )=6

14-(     )=6

16-(     )=2

13-(     )=13

14-(     )=4

(     )-15=4

(     )-10=9

20-(     )=17

(     )-1=15

(     )-12=3

11-(     )=8

(     )-12=7

12-(     )=5

17-(     )=0

(     )-14=1

(     )-14=6

13-(     )=4

(     )-9=3

14-(     )=10

(     )-11=1

18-(     )=1

(     )-9=8

(     )-9=6

(     )-17=3

12-(     )=11

17-(     )=9

14-(     )=4

19-(     )=5

14-(     )=14

12-(     )=9

(     )-9=8

17-(     )=17

(     )-8=4

(     )-10=10

(     )-3=10

(     )-18=0

(     )-8=5

19-(     )=8

20-(     )=9

13-(     )=6

16-(     )=13

13-(     )=1

(     )-4=13

13-(     )=10

(     )-0=11