20. $158, 400 - multiply 40 by 22 to get the total square footage(880), then multiply 880 by 15 to get they total for the month, which is 13,200. lastly, you take 13,200 multiplied by 12(for each month in a year), and you get $157,400.
Add like terms just like you would anywhere else...
Hey there!

Anything to the power of 0 is 1. So that means x can be equal to any number. Let's say 1^0, it will still equal 1. 2^0 is also equal to 1. X is therefore not a number since it can be anything.

Hope this helps!

Honestly, I would go with:
C. Yes, because the mean is larger in the math book
Because the mean for the math book is 49.9 and the poetry book's mean is 41.5. And since 49.9 is a bigger number than 41.5, that is why i'm going with that one
But it's for sure one of the bottom 2
Hope this helps!! :-)