0=-4.9t^2+30.5t+8.8

Solution for 0=-4.9t^2+30.5t+8.8 equation:

0=-4.9t^2+30.5t+8.8

We move all terms to the left:

0-(-4.9t^2+30.5t+8.8)=0

We add all the numbers together, and all the variables

-(-4.9t^2+30.5t+8.8)=0

We get rid of parentheses

4.9t^2-30.5t-8.8=0

a = 4.9; b = -30.5; c = -8.8;
Δ = b2-4ac
Δ = -30.52-4·4.9·(-8.8)
Δ = 1102.73
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{-(-30.5)-\sqrt{1102.73}}{2*4.9}=\frac{30.5-\sqrt{1102.73}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30.5)+\sqrt{1102.73}}{2*4.9}=\frac{30.5+\sqrt{1102.73}}{9.8}
$