Check my proof? two diagonals of a parallelogram bisect each other?

If a and −a are numbers on the number line, which expression must give the distance between them? a) 0 b) a c) |2a| d) |a|

Determine if the solution set for the system of equations shown is the empty set, contains one point or is infinite. x + y = 5 x + y = 7 {} 1 solution infinite

Maryann’s friends loved her bulletin board, and 4 of them asked her to make one for their homes. she offered to make each of her friends a replica of her bulletin board that measures 2 meters by 3 meters. how many kilograms of burlap should maryann collect to complete the bulletin boards for her friends? maryann should collect kg of burlap.