Idon't get traditional algorithm

Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

In an equilateral triangle, each angle is represented by 5y+3. what is the value of y? a. 9.7 b. 10.8 c. 11.4 d. 7.2

Ahighway between points a and b has been closed for repairs. an alternative route between there two locations is to travel between a and c and then from c to b what is the value of y and what is the total distance from a to c to b?