39,2=5t^2

Solution for 39,2=5t^2 equation:

39.2=5t^2

We move all terms to the left:

39.2-(5t^2)=0

a = -5; b = 0; c = +39.2;
Δ = b2-4ac
Δ = 02-4·(-5)·39.2
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-28}{2*-5}=\frac{-28}{-10}
=2+4/5
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+28}{2*-5}=\frac{28}{-10}
=-2+4/5
$