Let's first calculate the time it took to travel the first distance:
Time = Distance / Speed
Time = (2x + 13) / 67.5
Next, let's calculate the time it took to travel the second distance:
Time = Distance / Speed
Time = (5x - 20) / 72
Since the total time for the entire journey was 90 minutes, we can write the equation:
(2x + 13) / 67.5 + (5x - 20) / 72 = 90/60
Simplify the equation:
(2x + 13) / 67.5 + (5x - 20) / 72 = 1.5
Multiply everything by 67.5 and 72 to eliminate the fractions:
72(2x + 13) + 67.5(5x - 20) = 1.5 * 67.5 * 72
Expand and simplify:
144x + 936 + 337.5x - 1350 = 6075
481.5x - 414 = 6075
481.5x = 6489
Now, divide by 481.5 to solve for x:
x = 13.47
Therefore, the value of x is 13.47.
A car travelled a distance of (2x+13) km at 67,5 km/h and (5x-20) km at 72 km/h. If the total time for the entire journey was 90 minutes, find the value of x.
1 answer