Help me with the unanswered ones pleeeease!

15. 6 - -3 = 6 + 3 = 9. Answer: 9 degrees C
16. 7 - -7 = 7 + 7 = 14. Answer: 14 degrees F
17. -1 - -5 = -1 + 5 = 4. Answer: 4 degrees C
18. 5 - -2 = 5 + 2 = 7. Answer: 7 degrees C
19. 130 - -110 = 130 + 110 = 240. Answer: 240 degrees C
Answer:
15. 9 degrees C
16. 14 degrees F
17. 4 degrees C
18. 7 degrees C
19. 240 degrees C
Step-by-step explanation:
15. 6+3=9
16. 7+7=14
17. -1 + 5=4
18. 5+2=7
19. 130+ 110= 240