0=-0.8t^2+6t-8

Solution for 0=-0.8t^2+6t-8 equation:

0=-0.8t^2+6t-8

We move all terms to the left:

0-(-0.8t^2+6t-8)=0

We add all the numbers together, and all the variables

-(-0.8t^2+6t-8)=0

We get rid of parentheses

0.8t^2-6t+8=0

a = 0.8; b = -6; c = +8;
Δ = b2-4ac
Δ = -62-4·0.8·8
Δ = 10.4
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)-\sqrt{10.4}}{2*0.8}=\frac{6-\sqrt{10.4}}{1.6}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+\sqrt{10.4}}{2*0.8}=\frac{6+\sqrt{10.4}}{1.6}
$