X^2-2x-4=1.6

Solution for X^2-2x-4=1.6 equation:

X^2-2X-4=1.6

We move all terms to the left:

X^2-2X-4-(1.6)=0

We add all the numbers together, and all the variables

X^2-2X-5.6=0

a = 1; b = -2; c = -5.6;
Δ = b2-4ac
Δ = -22-4·1·(-5.6)
Δ = 26.4
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{-(-2)-\sqrt{26.4}}{2*1}=\frac{2-\sqrt{26.4}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+\sqrt{26.4}}{2*1}=\frac{2+\sqrt{26.4}}{2}
$