Will give out medals for help!

Flight path equations:
The Diligent - s(t)=-0.05t(t-20)
High Flyer - s(t) = -0.001t(t+35)(t-35)
Resplendent - s(t) = -0.1t(t-28)

Use the flight path equations to determine algebraically:
What time each plane returned.
Which plane arrived back first (I can figure that bit out if you help!)

Thank you in advance!

Question

Will give out medals for help!

Flight path equations: 
The Diligent - s(t)=-0.05t(t-20)
High Flyer - s(t) = -0.001t(t+35)(t-35)
Resplendent - s(t) = -0.1t(t-28)

Use the flight path equations to determine algebraically:
What time each plane returned.
Which plane arrived back first (I can figure that bit out if you help!)

Thank you in advance!

agent0smith · Answer

Set each equation equal to zero, solve for t in each.

anonymous · Answer

Thank you! I figured it would be something like that, I'm just never consistent with my answers so I doubt myself all the time. 

Thanks! I'll let you know if I still have trouble.

agent0smith · Answer

Keep in mind when you get a value for t that is either negative or zero, then those are not the ones you're looking for.

anonymous · Answer

Thanks again :)