10=-16t^2+85t+4

Solution for 10=-16t^2+85t+4 equation:

10=-16t^2+85t+4

We move all terms to the left:

10-(-16t^2+85t+4)=0

We get rid of parentheses

16t^2-85t-4+10=0

We add all the numbers together, and all the variables

16t^2-85t+6=0

a = 16; b = -85; c = +6;
Δ = b2-4ac
Δ = -852-4·16·6
Δ = 6841
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{-(-85)-\sqrt{6841}}{2*16}=\frac{85-\sqrt{6841}}{32}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-85)+\sqrt{6841}}{2*16}=\frac{85+\sqrt{6841}}{32}
$