X^2+x=0,79

Solution for X^2+x=0,79 equation:

X^2+X=0.79

We move all terms to the left:

X^2+X-(0.79)=0

We add all the numbers together, and all the variables

X^2+X-0.79=0

a = 1; b = 1; c = -0.79;
Δ = b2-4ac
Δ = 12-4·1·(-0.79)
Δ = 4.16
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{-(1)-\sqrt{4.16}}{2*1}=\frac{-1-\sqrt{4.16}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{4.16}}{2*1}=\frac{-1+\sqrt{4.16}}{2}
$