Look at photo and tell me the answer

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

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

Having a hard time understanding this question (see attachment).