11-6x=0.8x2

Solution for 11-6x=0.8x2 equation:

11-6x=0.8x^2

We move all terms to the left:

11-6x-(0.8x^2)=0

We get rid of parentheses

-0.8x^2-6x+11=0

a = -0.8; b = -6; c = +11;
Δ = b2-4ac
Δ = -62-4·(-0.8)·11
Δ = 71.2
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{-(-6)-\sqrt{71.2}}{2*-0.8}=\frac{6-\sqrt{71.2}}{-1.6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+\sqrt{71.2}}{2*-0.8}=\frac{6+\sqrt{71.2}}{-1.6}
$