H=9.8t^2+10t+2

Solution for H=9.8t^2+10t+2 equation:

=9.8H^2+10H+2

We move all terms to the left:

-(9.8H^2+10H+2)=0

We get rid of parentheses

-9.8H^2-10H-2=0

a = -9.8; b = -10; c = -2;
Δ = b2-4ac
Δ = -102-4·(-9.8)·(-2)
Δ = 21.6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$H_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$H_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$H_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-\sqrt{21.6}}{2*-9.8}=\frac{10-\sqrt{21.6}}{-19.6}
$
$H_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+\sqrt{21.6}}{2*-9.8}=\frac{10+\sqrt{21.6}}{-19.6}
$