Alis is in 20km race.He always run 2km/hr fast in first half then second half If x represent speed of first half then determine expression in term of x for total time needed for race

It's a little hard to understand your question but is this it:

Alis runs a 20km race running 2km/hr in the first half and if the first half speed (2km/hr) is x then what expression with x is the speed alis runs in the second half.

Well, this question has infinite answers because the question doesn't say the total time Alis takes to run the race, but I'll give an example of how to solve this problem with a made up time.

I guess you mean if the speed with which he runs the second half is x,.

Then, the time he takes for the first half distance is:



The time he takes for the second half distance is:



Total time =

Or did you mean something else? :confused:

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Alis is in 20km race.
He always run 2km/hr faster in first half then second half.
If x represent speed of first half then determine expression in term of x for total time needed for race.

I merged your posts. Your question already received help, so read it first and tell us what you think instead of re-posting your question. Thanks!