0.3+5.5t=-4.9t^2

Solution for 0.3+5.5t=-4.9t^2 equation:

0.3+5.5t=-4.9t^2

We move all terms to the left:

0.3+5.5t-(-4.9t^2)=0

We get rid of parentheses

4.9t^2+5.5t+0.3=0

a = 4.9; b = 5.5; c = +0.3;
Δ = b2-4ac
Δ = 5.52-4·4.9·0.3
Δ = 24.37
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{-(5.5)-\sqrt{24.37}}{2*4.9}=\frac{-5.5-\sqrt{24.37}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5.5)+\sqrt{24.37}}{2*4.9}=\frac{-5.5+\sqrt{24.37}}{9.8}
$