Mark averaged 60 miles per hour during the 30-mile trip to college. Because of heavy traffic he was able to average only 30 miles per hour during the return trip. What was Mark's average speed for the round trip

Which of the following correctly justifies statement four of the two column proof? a. corresponding angles theorem b. transitive property of equality c. vertical angle theorem d. substitution property of equality

Secant be and cf intersect at point d inside a what is the measure of cde

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