-16t^2+64t=39

Solution for -16t^2+64t=39 equation:

-16t^2+64t=39

We move all terms to the left:

-16t^2+64t-(39)=0

a = -16; b = 64; c = -39;
Δ = b2-4ac
Δ = 642-4·(-16)·(-39)
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(64)-40}{2*-16}=\frac{-104}{-32}
=3+1/4
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(64)+40}{2*-16}=\frac{-24}{-32}
=3/4
$