In this one, you must make h = 0.
You get : [tex]-16t^2-4t+70[/tex] which can be further simplified to [tex]8t^2+2t-35[/tex] if you divide all of the numbers by -2.
Here you can use the quadratic formula again!
You get the numbers to be : 1.97 and -2.22
I had made a mistake to think that negative numbers can be included but in these questions, you can't have negative numbers as your answer. So the correct answer is 1.97!