H=39t-5t2 find all the values of t for which the rockets hight is 22 meters

I believe that for this question you will use the quadratic equation which is: (-b +/- sqrt(b^2-4(a)(c))/2a   Plug in -5=a, 39=b, 22=c and that should give you 2 answers for t.  

Option a : week- amuont paid