Answer:
3n^2-n+9
Explanation:
You would want to divide the 5 between each of the terms. 15n^2 ÷ 5 is 3n^2. 15 ÷ 5 is 3. The n^2 stays, so 3n^2. -5 ÷ 5 is -1. We don't have to worry about writing the -1. Rather, just write the -n, it is the same as writing -1n. Lastly, 45 ÷ 5 is 9. You have to put the terms together in standard form. Standard form is just writing the numbers from greatest power to least power. The 3n^2 would come first since 2 is the greatest power. Next would be the -n, and lastly the 9. The 9 is the constant, which always comes last. A constant would be a number without a variable after it, like 2x is not a constant but just 2 is. Therefore, the answer is 3n^2-n+9.