To find the average, add the cost of each book to get a total cost, then divide the total cost by the number of books purchased.
Total cost: 32 + 45 + 39 = 116
Average cost: 116 / 3 = 38.67
So assuming the underlined decimal is the second 8, let's answer the question.
Hundreds: 0 | Tens: 8 | ones: 3 | . | tenths: 5 | hundredths: 8 | thousandths: 5 | 10 thousandths: 1
So since the second 8 is in the hundredths place, we know it's either B or C.
When we round for 5, we always round up, so the answer would be 83.59
So the answer is B.
Hope this helped! If you have any more questions or don't understand please comment or DM me. :)
Simple...
you have:

To make this into an improper fraction-->>
1.) Multiply whole number by denominator
2.)Add the number you got plus the numerator
3.) Use the original denominator to finish your improper fraction
Example:

4*9=36
36+4=40

Thus, your answer.
You'll set the two expressions equal to 95.
So 2x+119=95
Then 2x=-24
Finally x=-12