If the length of the first room is (2x+7) and the length of the second room is (2x - 1), which expression models the area of the new room once the wall is knocked down?
6x +12
O
4x2+18
4x2+ 13x-4
4x+18x +18

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?

Divide. write in the simplest form. 4 1/6 divided by 10

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?