X2-2x=2.5

Solution for X2-2x=2.5 equation:

X2-2X=2.5

We move all terms to the left:

X2-2X-(2.5)=0

We add all the numbers together, and all the variables

X^2-2X-2.5=0

a = 1; b = -2; c = -2.5;
Δ = b2-4ac
Δ = -22-4·1·(-2.5)
Δ = 14
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{14}}{2*1}=\frac{2-\sqrt{14}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+\sqrt{14}}{2*1}=\frac{2+\sqrt{14}}{2}
$