I believe the answer is 17
The first number is x axis while the second is y

the first step is to deal with the negative exponents, which causes numbers to go to the other side of the fraction
8x^{-9}+(-3x^{-3}y^{-2})(\frac{5}{x^6y^{-2}})
goes to

now we can simplify the multiplied terms

Now that we have common bases, we can add the 2 fractions together to get

Answer: Choice B) -5.2 degrees
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Work Shown:
Add up the given temperatures
-42 + (-17) + 14 + (-4) + 23 = -26
Then divide by 5 since there are 5 values we're given
-26/5 = -5.2