A number decreased by the sum of the number and four and please show the steps
1 answer:
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Answer:
Step-by-step explanation:
Hello,
(a) Peter cycle at an average speed of x km/h
it means that he is doing x km in 1 hour
so to do 40 km he needs 40/x hour
(b) it means that he was doing x-5 km/h
so it took 40/(x-5) hour
(c) 1 hour 20 minutes correspond to 1+20/60=1+1/3=4/3 hour as 1 hour is 60 minutes
so we can write
40/(x-5)=40/x+4/3
(d)
the speed is positive so we take the positive solution which is 15
the speed is 15 km/h
hope this helps
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