You first identify what supplementary angles are,angles that add up to 180.
5x+2+8x+9=180
17x+11=180-11
17x=169
x=169divided by 17
x=9.9411
x=10 when rounded into the next value
8x*10=80+989
2: Linear Pair Postulate
3: Congruent Supplement Theorem
Finding the difference between the two temperatures, it is found that Regina is 38.7ºC degrees colder in January than in July.
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- The mid-afternoon temperature in January is of -12.6ºC.
- In July, it is of 26.1ºC.
- The difference of the temperatures is given by:

From the difference of 38.7ºC, there are two interpretations:
- Regina is 38.7ºC degrees colder in January than in July.
- Regina is 38.7ºC degrees warmer in July than in January.
A similar problem is given at brainly.com/question/22136310