Question

Nick can do a certain job in 3 hours less than it takes bonnie to do the same job. If they complete the job together in 9 hours, what equation could be used to determine how long it will take bonnie to do the job alone

Answer 1

Explanation:

Let the number of hours Nick does the job alone to be x - 3 hours

Hence, in 1 hour, Nick has done 1/x - 3

Together they complete the job in 9 hours

Hence, let's represent the job as 1

9/x + 9/x - 3 = 1

Multiply through by (x)(x-3)

9(x- 3) + 9(x) = 1

9x - 27 + 9x = (x)(x-3)

-27 = x² - 3x

x² - 3x +27 = 0