The difference of two numbers.(a, b) is 21. the difference of 5 times a and 2 times b is 18. what are the values of a, b?

Is every rectangle is a parallelogram? true false

Tamera puts 15/4 gallons of gasoline in her car. which mixed number represents the gallons of gasoline? a) 2 3/4 gallons b) 3 1/4 gallons c) 3 3/4 gallons d) 4 1/2 gallons answer it's worth a lot of points!

D(5, 7). e(4,3), and f(8, 2) form the vertices of a triangle. what is mzdef? oa. 30° ob. 45° oc. 60° od 90°