Derrick is building a treehouse for his younger brother. The treehouse will take 85 1/4 hours to complete. Derrick spends 17 1/20 hours on it each weekend. If he has already worked on it for 3 weeks, how many more weeks will he need to work on it until it is complete?
Please provide a step by step answer if you can :'(

2 more weeks

Step-by-step explanation:

First, determine how many weekends will be required for Derrick to complete the treehouse:

 85 1/4 hours total       85.25 hrs

= = 5 weeks

17 1/20 hrs/wk              17.05 hrs/ wk

Derrick has already worked 3 weeks, and so he should be able to complete the treehouse in 2 more weeks (2 + 3 = 5).

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!

your answer would be 12