I suck at distance problems. Please help

Question

Hillary started biking to the study group traveling 14 mph, after some time the bike got a flat so Hillary walked the rest of the way, traveling 3 mph. If the total trip to the study group took 7 hours and it was 65 miles away, how long did Hillary travel at each speed?

Answer 1

65 miles = distance biking +  distance walking

 

             =  14 mph x time biking + 3 mph x time walking

 

 

7 hours = time biking + time walking

 

Let Tb = time biking and Tw = time walking.

 

65 = 14 * Tb + 3 * Tw

 

7 = Tb +Tw  ---> 7 - Tw = Tb

 

65 = 14 ( 7 - Tw) + 3 * Tw

 

65 = 98 - 14 * Tw + 3 * Tw

 

65 = 98 - 11 * Tw

 

11 * Tw = 98 - 65

 

11 * Tw = 33

 

Tw = 3

 

 

CHECK:

3*3 + 4*14 = 9 + 56 = 65

 

She spent 3 hours walking

She spent 4 hours riding the bike.

 

 

 

 

Answer 2

d_biking = 14t

d_walking = 3(7 - t)

d_biking + d_walking = 65

14t +3(7- t) = 65

 

Can you solve for t and answer?