36=16t^2+36t

Solution for 36=16t^2+36t equation:

36=16t^2+36t

We move all terms to the left:

36-(16t^2+36t)=0

We get rid of parentheses

-16t^2-36t+36=0

a = -16; b = -36; c = +36;
Δ = b2-4ac
Δ = -362-4·(-16)·36
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-60}{2*-16}=\frac{-24}{-32}
=3/4
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+60}{2*-16}=\frac{96}{-32}
=-3
$