560 mile trip. spent 2 hours more on interstate highways than on local highways. they were driving 45 mph on local and 55 on interstate. how many hours were spent on local highways ?

Let x be the number of hours spent on the local highways and y be the number of hours spent on the interstate highways. They spent two more hours on the interstate highway than the local highways, so y = x + 2. The distance formula is d = rt (distance = rate*time), so the distance the team traveled on the local highways alone was 45x miles. Likewise, the distance the team traveled on the interstate highways alone was 55y miles. In total, they traveled 560 miles, so 45x + 55y = 560. 
Solve the system of equations using substitution. 
45x + 55y = 560 (substitute x + 2 for y) 45x + 55(x + 2) = 560 45x + 55x + 110 = 560 100x + 110 = 560 100x = 450 x = 4.5 hours on the local highways
So the answer would be 4.5 hours. That is the answer if my math is correct if it is wrong I am sorry but I think it is correct I am just trying to help.