-16t^2+400=0
16t^2=400
take square root on both sides.

4t=20
t=20/4
t=5
253. First, I squared 8, to get 64, then multiplied that by 12. I subtracted 9 from this because 3x3 is 9 to get 759. Then, divide this by 3 to get 253. Hope this helped!
Answer: Quedarían nueve
Step-by-step explanation:
There is a way and you will find it but not from me