Thread: A cyclist travels 40 km at a speed x km/h. Find the time taken in terms of x etc.

Hello! I would like some help with this task.

A cyclist travels 40 km at a speed x km/h. Find the time taken in terms of x. Find the time taken when his speed is reduced by 2 km/h. If the difference between the times is 1 hour, find the orginal speed, x km/h.

Thank you!

Originally Posted by Anna55

Hello! I would like some help with this task.

A cyclist travels 40 km at a speed x km/h. Find the time taken in terms of x. Find the time taken when his speed is reduced by 2 km/h. If the difference between the times is 1 hour, find the orginal speed, x km/h.

Thank you!

Hi Anna55,

Using , we first have:





After decreasing the rate by 2 km/h, we have:





The difference in time is 1 hour. So...



Can you finish up?

Thank you. I understand everything except why you are doing this (x+2)t=40 when is speed are reduced by 2km/h.

Originally Posted by Anna55

Thank you. I understand everything except why you are doing this (x+2)t=40 when is speed are reduced by 2km/h.

I misread your problem. Just change the + to a -. And reverse the order of the subtraction. Sorry! I'll edit my post so you can see.

Thank you! I tried to solve the equation, however I cannot. First I extended the denominator so every fraction hade the same denominator (x-2) x. After that I moved over 1 to the left side so everything equaled 0. After that I cannot continue. Can you please show me.

Originally Posted by Anna55

Thank you! I tried to solve the equation, however I cannot. First I extended the denominator so every fraction hade the same denominator (x-2) x. After that I moved over 1 to the left side so everything equaled 0. After that I cannot continue. Can you please show me.

Hi Anna55,

Sorry for the confusion initially. Here is the complete solution.



Multiply each side by











Disregard the negative solution.

Thank you very much masters! I understand everything now.