Which of these strategies would eliminate a variable in the system of equations -7x+2y=5 and 3x-5y=-5

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

Me. i can't figure out this question. give an explanation too. .

I'm confused on this could anyone me and show me what i need to do to solve it.