Helpp x/3 -10 11

(#1 in the picture)

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

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?

Acircle has a circumference of 28.36 units what is the diameter of the circle