SOLUTION: Pls help me with this question. James walks a distance of 10km at an average speed of xkm/h.Jane walks the same distance at (x-1)km/h.If the difference in their times is 30minutes,

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Question 271711: Pls help me with this question. James walks a distance of 10km at an average speed of xkm/h.Jane walks the same distance at (x-1)km/h.If the difference in their times is 30minutes, find the value of x.
Answer by dabanfield(803) About Me  (Show Source):
You can put this solution on YOUR website!
Pls help me with this question. James walks a distance of 10km at an average speed of xkm/h.Jane walks the same distance at (x-1)km/h.If the difference in their times is 30minutes, find the value of x.
Let t be the time needed for James to walk the distance:
Then since distance = rate x time we have:
1.) 10 = x*t or
t = 10/x
Jane walks the same distance in t+30 so we have:
2.) 10 = (x-1)*(t+30)
Substitute 10/x for t in equation 2.) giving:
10 = (x-1)*((10/x)+30)
10 = (10/x)*x - 10/x +30x - 30
10 = 10 - 10/x + 30x - 30
30x - 10/x = 30
Multiply both sides above by x:
30x^2 - 10 = 30x
30x^2 - 30x - 10 = 0
Solve the above quadratic equation for x using the quadratic formula.