-5=-0.6x^2+3x+6

Solution for -5=-0.6x^2+3x+6 equation:

-5=-0.6x^2+3x+6

We move all terms to the left:

-5-(-0.6x^2+3x+6)=0

We get rid of parentheses

0.6x^2-3x-6-5=0

We add all the numbers together, and all the variables

0.6x^2-3x-11=0

a = 0.6; b = -3; c = -11;
Δ = b2-4ac
Δ = -32-4·0.6·(-11)
Δ = 35.4
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{-(-3)-\sqrt{35.4}}{2*0.6}=\frac{3-\sqrt{35.4}}{1.2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+\sqrt{35.4}}{2*0.6}=\frac{3+\sqrt{35.4}}{1.2}
$