Respuesta :
Answer:
40 minutes
Step-by-step explanation:
Let c represent the number of minutes it would take colleen to finish the job when he is working alone. Hence, it can be represented by the equation:
[tex]\frac{1}{c}+\frac{1}{c+20} =\frac{1}{24} \\\\Finding\ the\ L.C.M\ of\ the\ fraction\ to\ get\ 24c(c+20)\ as\ the\ L.C.M.\\Multiply\ the\ whole\ equation\ by\ 24c(c+20):\\\\\frac{1}{c}(24c(c+20))+\frac{1}{c+20}(24c(c+20)) =\frac{1}{24}(24c(c+20)) \\\\24c+480+24c=c^2+20c\\\\48c+480=c^2+20c\\\\c^2+20c-48c-480=0\\\\c^2-28c-480=0[/tex]
Solving the quadratic equation to get c gives:
c = -12 and c = 40
Since the time cannot be negative, hence c = 40 minutes.
It would take colleen 40 minutes to clear the yard of leaves alone
Answer:
40 minutes
Step-by-step explanation:
I got it right on my test.