PM 1

1. 1. $15+(-8)=\dots$
   2. $-12+7=\dots$
   3. $18-(-6)=\dots$
   4. $-9-5=\dots$
   5. $24+(-15)=\dots$
   6. $-17+9=\dots$
   7. $13-(-4)=\dots$
   8. $-20-(-8)=\dots$
   9. $11+(-19)=\dots$
   10. $-25+16=\dots$
   11. $27-13=\dots$
   12. $-14-(-7)=\dots$
   13. $8+(-12)=\dots$
   14. $-6+18=\dots$
   15. $30-(-10)=\dots$
   16. $-22-9=\dots$
   17. $19+(-5)=\dots$
   18. $-15+(-8)=\dots$
   19. $21-(-14)=\dots$
   20. $-28-(-12)=\dots$
   21. $16+(-20)=\dots$
   22. $-9+25=\dots$
   23. $14-18=\dots$
   24. $-30-(-15)=\dots$
   25. $7+(-9)=\dots$
   26. $-18+11=\dots$
   27. $26-(-7)=\dots$
   28. $-13-6=\dots$
   29. $22+(-13)=\dots$
   30. $-24+(-16)=\dots$

   
   

1.The temperature inside a cooling room was initially 5°C. After operating for 4 hours, the temperature became −11°C. The difference in temperature before and after operating is ...

2. The temperature of a freezer was initially 8°C. After being turned on for several hours, the temperature dropped to −7°C. What is the difference between the initial and final temperatures?

3. A cold storage room had an initial temperature of 2°C. After cooling overnight, its temperature became −14°C. Find the difference in temperature...

4.The temperature inside a refrigerator was 6°C before it was switched on. After 2 hours, the temperature became −9°C. Calculate the difference between the two temperatures.

5. A laboratory cooling chamber was initially at 10°C. After being operated for 5 hours, the temperature decreased to −8°C. What is the difference in temperature before and after it was turned on?