x^2+0.8x-1.84=0

Solution for x^2+0.8x-1.84=0 equation:

x^2+0.8x-1.84=0

a = 1; b = 0.8; c = -1.84;
Δ = b2-4ac
Δ = 0.82-4·1·(-1.84)
Δ = 8
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{8}=\sqrt{4*2}=\sqrt{4}*\sqrt{2}=2\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0.8)-2\sqrt{2}}{2*1}=\frac{-0.8-2\sqrt{2}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.8)+2\sqrt{2}}{2*1}=\frac{-0.8+2\sqrt{2}}{2}
$