860=4.9t^2+22.1t

Solution for 860=4.9t^2+22.1t equation:

860=4.9t^2+22.1t

We move all terms to the left:

860-(4.9t^2+22.1t)=0

We get rid of parentheses

-4.9t^2-22.1t+860=0

a = -4.9; b = -22.1; c = +860;
Δ = b2-4ac
Δ = -22.12-4·(-4.9)·860
Δ = 17344.41
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{-(-22.1)-\sqrt{17344.41}}{2*-4.9}=\frac{22.1-\sqrt{17344.41}}{-9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-22.1)+\sqrt{17344.41}}{2*-4.9}=\frac{22.1+\sqrt{17344.41}}{-9.8}
$