Some harry can rake the leaves in the yard 8 hours faster than his little brother jimmy can. if they work together, they can complete the job in 3 hours. using complete sentences, explain each step in figuring out how to determine the time it would take jimmy to complete the job on his own.

use rates, the rate a person is working is the reciprocal of the time working together, they work at a rate of 1/3 job per hour when two people work together their rates add together ---> 1/h + 1/j = 1/3 ---> h = j - 8 (harry takes 8 hrs less than jimmy) substitute and solve for j

1j−8+1j=13 combine fractions j+(j−8)j(j−8)=13 cross-multiply j2−8j=6j−24 j2−14j+24=0 Factor (j−12)(j−2)=0 j = 12 It takes jimmy 12 hours to rake the leaves

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )