x^2+1.6x=0.36

Solution for x^2+1.6x=0.36 equation:

x^2+1.6x=0.36

We move all terms to the left:

x^2+1.6x-(0.36)=0

We add all the numbers together, and all the variables

x^2+1.6x-0.36=0

a = 1; b = 1.6; c = -0.36;
Δ = b2-4ac
Δ = 1.62-4·1·(-0.36)
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1.6)-2}{2*1}=\frac{-3.6}{2}
=-1+1/1.25
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.6)+2}{2*1}=\frac{0.4}{2}
=0.4/2
$