You do it be dividing the numerator and denominator by the same number, but you have to make sure the divide into whole numbers
No, its D
Just look at the rounds mentioned and subtract the scores from higher round with lower round.
Look at A: round 2 score - round 1 score = -2?
-3 -1 = -4 change, not -2 change so it is wrong
Look at B: round 3 score - round 1 score =-1?
-2-1 =-3 change, not -1 change so it is wrong
Look at C: round 3 score - round 2 score =-1?
-2 -(-3) = 1 change, not -1 change so it is wrong
Look at D: round 3 score - round 1 score =-3?
-2-1 = -3 change, matches with -3 so it is correct.
For this case we have the following quadratic functions:
Revenue: 
Cost: 
Then, we observe that the profit is given by the following mathematical relationship:

Substituting values we have:

Making the corresponding calculations we have:

Answer:
An expression that represents the profit is:

8.605
This number is bigger than 6.604 and it is smaller than 8.643
:)