3.4=-0.8x^2-0.06x+3.4

Solution for 3.4=-0.8x^2-0.06x+3.4 equation:

3.4=-0.8x^2-0.06x+3.4

We move all terms to the left:

3.4-(-0.8x^2-0.06x+3.4)=0

We get rid of parentheses

0.8x^2+0.06x-3.4+3.4=0

We add all the numbers together, and all the variables

0.8x^2+0.06x=0

a = 0.8; b = 0.06; c = 0;
Δ = b2-4ac
Δ = 0.062-4·0.8·0
Δ = 0.0036
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0.06)-\sqrt{0.0036}}{2*0.8}=\frac{-0.06-\sqrt{0.0036}}{1.6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.06)+\sqrt{0.0036}}{2*0.8}=\frac{-0.06+\sqrt{0.0036}}{1.6}
$