let the speed of the slower bus be equal to x miles per hour
let the speed of the faster bus be equal to x+14 miles per hour
after every hour they would be a further 2x+14 miles apart from eachother
therefore after 4 hours they would be 4(2x+14) = 8x + 56 miles away from eachother
since we know exactly how many miles this is we can solve for x
8x + 56 = 496
8x = 440
x = 55
x + 14 = 69
therefore, the speed of the slower bus is 55 mph whereas the speed of the faster bus is 69 mph
