0=-4.9t^2+6.5t+2.0

Solution for 0=-4.9t^2+6.5t+2.0 equation:

0=-4.9t^2+6.5t+2.0

We move all terms to the left:

0-(-4.9t^2+6.5t+2.0)=0

We add all the numbers together, and all the variables

-(-4.9t^2+6.5t+2.0)=0

We get rid of parentheses

4.9t^2-6.5t-2.0=0

We add all the numbers together, and all the variables

4.9t^2-6.5t-2=0

a = 4.9; b = -6.5; c = -2;
Δ = b2-4ac
Δ = -6.52-4·4.9·(-2)
Δ = 81.45
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{-(-6.5)-\sqrt{81.45}}{2*4.9}=\frac{6.5-\sqrt{81.45}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6.5)+\sqrt{81.45}}{2*4.9}=\frac{6.5+\sqrt{81.45}}{9.8}
$