What is the coefficient in -x^2?

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar. consider the given table.

The surface area of the triangular prism is .