Answer:
speed of the Jon visiting parents = 56 mph
speed of the Jon when returning from home = 56 - 14 = 42 mph
Explanation:
given,
distance of Jon parent's house = 648 mile
avg speed when he was visiting his parent's house be 'x' mph
avg speed when he is returning from his parent's house be 'x-14' mph
total time taken = 27 hours
total distance = speed × time
648 = x × t₁
648 = ( x - 14 ) × t₂
t = t₁ + t₂
x² - 62 x + 336 = 0
x² - 56 x - 6 x + 336 = 0
(x - 56 )(x - 6)=0
on solving
x = 56 ,6
hence, speed of the Jon visiting parents = 56 mph
speed of the Jon when returning from home = 56 - 14 = 42 mph