x^2-14x=287

Solution for x^2-14x=287 equation:

x^2-14x=287

We move all terms to the left:

x^2-14x-(287)=0

a = 1; b = -14; c = -287;
Δ = b2-4ac
Δ = -142-4·1·(-287)
Δ = 1344
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:

$\sqrt{\Delta}=\sqrt{1344}=\sqrt{64*21}=\sqrt{64}*\sqrt{21}=8\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-8\sqrt{21}}{2*1}=\frac{14-8\sqrt{21}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+8\sqrt{21}}{2*1}=\frac{14+8\sqrt{21}}{2}
$