Question 878737
Number 1 item could be analyzed by filling a data table for rate, time, distance; the question is a uniform rates for travel type.


r = speed for bicycle
t =  time for bicycle


__________________speed___________time_________distance
motorcycle________r+15____________t-2__________60
bicycle____________r_______________t___________60


The number 1 item does not actually contain a question; it only contains a description.  No matter, because you specified that you want a mathematical sentence.  RT=D for rate, time, distance.  The rate unit is kilometers per hour.  You can first form TWO equations:
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(r+15)(t-2)=60
and
rt=60
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How much more do you need from that?


{{{rt+15t-2r-30=60}}}
{{{rt+15t-2r-30=rt}}}, using substitution with the other equation
{{{15t-2r-30=0}}}
Which do you want to finish solving first?  t or r ?
My choice..... using the second equation again, {{{r=60/t}}},
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{{{15t-2(60/t)-30=0}}}
{{{t-8/t-2=0}}}, just divided both sides by 15.
{{{highlight_green(t^2-8t-2t=0)}}}, just multiplied both sides by t.


Use the general solution of a quadratic formula, and select the meaningful result for t.  Use it to solve for r.