Question

d=vt+1/2at^2 solve for t

Answer 1

\[
\left(\frac 12 a\right)t^2+(v)t+(-d) = 0
\]

Answer 2

Are you familiar with the quadratic equation?

Answer 3

quadratic formula^

Answer 4

http://www.purplemath.com/modules/quadform.htm

In this case the variable is \(t\) instead of \(x\).