I'm taking Algebra 2, this is from the quadratics section. I'm not asking you to do my homework, but please, tell me how. I really appreciate the help. Here's the question:

In an engineering test, a rocket sled is propelled into a target. The sled’s distance d in meters from the target is given by the formula where t is the number of seconds after rocket ignition. How many seconds have passed since rocket ignition when the sled is 10 meters from the target?

I think most of my issue is that I don't quite know what to do with the 10, but I'm not sure.

Thank you for taking the time to read my post.