8t^2-14t-85=0

Solution for 8t^2-14t-85=0 equation:

8t^2-14t-85=0

a = 8; b = -14; c = -85;
Δ = b2-4ac
Δ = -142-4·8·(-85)
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-54}{2*8}=\frac{-40}{16}
=-2+1/2
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+54}{2*8}=\frac{68}{16}
=4+1/4
$