0=-16t^2+28.7t+32.4

Solution for 0=-16t^2+28.7t+32.4 equation:

0=-16t^2+28.7t+32.4

We move all terms to the left:

0-(-16t^2+28.7t+32.4)=0

We add all the numbers together, and all the variables

-(-16t^2+28.7t+32.4)=0

We get rid of parentheses

16t^2-28.7t-32.4=0

a = 16; b = -28.7; c = -32.4;
Δ = b2-4ac
Δ = -28.72-4·16·(-32.4)
Δ = 2897.29
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28.7)-\sqrt{2897.29}}{2*16}=\frac{28.7-\sqrt{2897.29}}{32}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28.7)+\sqrt{2897.29}}{2*16}=\frac{28.7+\sqrt{2897.29}}{32}
$