X2=1,369-3x-1^2

Solution for X2=1,369-3x-1^2 equation:

X2=1.369-3X-1^2

We move all terms to the left:

X2-(1.369-3X-1^2)=0

We add all the numbers together, and all the variables

X^2-(1.369-3X-1^2)=0

We get rid of parentheses

X^2+3X-1.369+1^2=0

We add all the numbers together, and all the variables

X^2+3X-0.369=0

a = 1; b = 3; c = -0.369;
Δ = b2-4ac
Δ = 32-4·1·(-0.369)
Δ = 10.476
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{10.476}}{2*1}=\frac{-3-\sqrt{10.476}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{10.476}}{2*1}=\frac{-3+\sqrt{10.476}}{2}
$