Question 389334
John t hrs
Bill (t+6) hrs
Together 4 hrs
Each contribute to this whole
{{{4/t + 4/((t+6)) = 1}}}
Multiply each side by t and by t+6
 4(t+6) + 4t = t(t+6)
4t + 24 + 4t = t^2 + 6t
Rearrange
{{{ t^2 - 2t - 24 = 0}}}
Solves as (t+4)(t-6) with t=6 as only real solution
John takes 6 hrs; Bill takes 12 hrs
Check: {{{4/6 + 4/((6+6)) = 2/3 + 1/3 = 1}}}


2. Using a graphing calculator find the roots of the equation to the nearest hundredth:
x^7+x^5-2x^3+3x^2-1=0