Question 1027267
Julio rides his bike for 6 miles and gets a flat tire.
 He then walks with the bike for another mile. His speed walking is 6 miles per hour less than his speed riding.
 if the total time of his trip was 1 hour, find his speed walking and his speed riding the bike.
:
let w = his walking speed
then
(w+6) = his riding speed
:
write a time equation; time = dist/ speed
:
 walk time + ride time = 1 hr
{{{1/w}}} + {{{6/((w+6))}}} = 1
multiply by w(w+6), cancel the denominators and you have
1(w+6) + 6w = w(w+6)
w + 6 + 6w = w^2 + 6w
Combine on the right to form a quadratic equation
0 = w^2 + 6w - 7w - 6
w^2 - w - 6 = 0
Factors to
(w-3)(w+2) = 0
positive solution is all we want here
w = 3 mph is his walking speed
then
3 + 6 = 9 mph is his riding speed
:
:
Confirm this, find the actual time for each
1/3 + 6/9 = 1