Equating algebra

A contractor charged a client $240 to paint a fence, estimating that the work would take a certain number of hours to complete. However, the contractor completed the work 2 hours earlier than estimated, resulting in a $6 increase in his per hour rate. How many hours did the contractor originally estimate the work would take?

When I factorize the quadratic equation, where t is time, I get (t-12)(t+10), i.e., t=12 and t=-10. yet, the answer here is 10. Some help please? Thanks!

Nevermind, messed up in the calculations, got the answer. Not able to delete this post for some reason, so here lies a mark of eternal embarrassment :’)

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t * r = 240
(t - 2)(r + 6) = 240
(t - 2)(\frac{240}{t} + 6) = 240
240 + 6t - \frac{480}{t} - 12 = 240
6t - \frac{480}{t} - 12 = 0
6t^2 - 480 - 12t = 0
t^2 - 80 - 2t = 0
t^2 -10t + 8t - 80 = 0
t(t - 10) + 8(t - 10) = 0
(t + 8) (t - 10)
t = -8, 10