The perimeter of the square below is 116 m. What is the value of a?
5a +9

Scarlet bought three pairs of sunglasses and two shirts for $81 and paula bought one pair of sunglasses and five shirts for $105 what is the cost of one pair of sunglasses and one shirt?

Ammonia molecules have three hydrogen atoms and one nitrogen atom.how many of each atom arein five molecules of ammonia

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25