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.
Its to scale. so every inch is 1.5 feet according to the statement of 18 inches being equal to 27 feet. In that case, the answer is C. because 20X1.5 is 30