The expression for the amount of time it took Miguel to run the
marathon the third time is 0.855 m
Step-by-step explanation:
Miguel has run three marathons
- The first time he ran a marathon, it took him m minutes
- The next time he ran he cut 10% off his time
- The third time he ran a marathon, he was able to cut an additional 5% off his fastest time (the time he got on the second marathon)
We need to write an expression for the amount of time it took Miguel
to run the marathon the third time
∵ It took him m minutes to run the first marathon
∵ In second marathon he cut 10% off his time
∴ The time of the second marathon = m - 10% × m
∵ 10% × m = (10/100) m = 0.1 m
∴ The time of the second marathon = m - 0.1 m = 0.9 m
∴ It took him 0.9 m minutes in the second marathon
∵ In the third marathon he cut additional 5% off his time in
the second marathon
∵ His time in the second marathon = 0.9 m
∴ The time of the third marathon = 0.9 m - 5% × 0.9 m
∵ 5% × 0.9 m = (5/100)(0.9 m) = 0.045 m
∴ The time of the third marathon = 0.9 m - 0.045 m = 0.855 m
∴ It took him 0.855 m minutes in the third marathon
The expression for the amount of time it took Miguel to run the
marathon the third time is 0.855 m
Learn more:
You can learn more about writing the expressions in brainly.com/question/13087541
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