What is the missing constant term in the perfect square that starts with x^2-20x

If n stands for number sold and c stands for cost per item, in which column would you use the formula: ? a. column d c. column f b. column e d. column g

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.

Jane has 5 nickels.john has 3 dimes.jane says she has a greater amount of money.with the information given,is she correct?