x2-x-15=159

Solution for x2-x-15=159 equation:

x2-x-15=159

We move all terms to the left:

x2-x-15-(159)=0

We add all the numbers together, and all the variables

x^2-1x-174=0

a = 1; b = -1; c = -174;
Δ = b2-4ac
Δ = -12-4·1·(-174)
Δ = 697
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{697}}{2*1}=\frac{1-\sqrt{697}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{697}}{2*1}=\frac{1+\sqrt{697}}{2}
$