Please help me with this question it is due :) question 4.

Simplify the expression. enter the correct answer.

Add 1/7 + -1/7 your answer should be reduced to its smallest form and should not be an improper fraction

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