The difference will be

.
Remember that parentheses are needed for the second polynomial because the negative is distributed to all of its terms.
15 - 9 + 2.65 + 1.35 + 3.48
6 + 2.65 + 1.35 + 3.48
8.65 + 1.35 + 3.48
10 + 3.48
13.48
Answer: an arithmetic sequence
Step-by-step explanation:
A is 400
E I don't know soory