Is a 120 angle acute or obtuse

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Handsome jack is buying a pony made of diamonds. the price of the pony is p dollars, and jack also has to pay a 25% diamond pony tax. which of the following expressions could represent how much jack pays in total for the pony?

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