PEMDAS
(9)(5) + 8
45 + 8
53
The calculated average of a data set best describes A: Mean.
When you compare two functions f(x) and g(x), you're looking for a special input 
such that
Since you have the table with some possible candidates for , you simply have to choose the row that gives values for f(x) and g(x) that are as close as possible (the exact solution would give the same value for f(x) and g(x), so the approximate solution will give values for f(x) and g(x) that are close to each other).
In your table, the values for f(x) and g(x) are closer when x=-0.75
1.68 mm per year for 1.5 years could be rewritten as
(2.00-0.32) mm per year for 1.5 yrs.
Multiply: (1.5 yrs)(2.00-0.32)(mm/yr) = 3 mm + 0.48 mm = 3.48 mm
This approach makes use of the distributive property of multiplication.
I would say Song 1 on the top could be NO, and Song 1 on the bottom could be ON, then Song 2 on the very top could be NO again, then on the bottom of the very top could OO, then on the bottom of that could be NN, and on he very bottom could be ON.
Hope this helps.
