A driver can travel 54 km at a constant speed. If he drives 3 km/h faster, he would have saved 3 km/h faster, he would have saved 3 hours. Let x be the speed of him originally, find the value of x.
solve for x:
54/x - 54/(x+3) = 3
(That's jogging speed. What is that person driving?)
btw, Steve gave you the same solution earlier this morning.
https://www.jiskha.com/questions/1756222/A-driver-can-travel-54-km-at-a-constant-speed-If-he-drives-3-km-h-faster-he-would
Why are you reposting the same question ?
To solve this problem, we can use the formula:
Distance = Speed * Time
Let's set up equations for both scenarios:
For the original speed, the driver can travel 54 km at a constant speed (x km/h). Therefore, we have:
54 = x * t (where t is the time taken in hours)
For the increased speed, the driver can travel the same distance (54 km) with a speed 3 km/h faster than the original speed (x + 3 km/h). Additionally, the driver would have saved 3 hours of travel time. So, we have:
54 = (x + 3) * (t - 3)
Now, we can solve these two equations simultaneously to find the value of x.
First, let's manipulate the second equation:
54 = (x + 3) * (t - 3)
54 = xt - 3x + 3t - 9
xt - 3x + 3t = 63
Now, let's rearrange the first equation:
54 = xt
From this equation, we can solve for t:
t = 54/x
Substitute this value of t into the manipulated second equation:
x(54/x) - 3x + 3(54/x) = 63
54 - 3x^2/x + 162/x = 63
54x - 3x^2 + 162 = 63x
3x^2 - 54x + 99 = 0
Now, we can simplify this quadratic equation and solve for x.