a^2-14a-47=0

Solution for a^2-14a-47=0 equation:

a^2-14a-47=0

a = 1; b = -14; c = -47;
Δ = b2-4ac
Δ = -142-4·1·(-47)
Δ = 384
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{384}=\sqrt{64*6}=\sqrt{64}*\sqrt{6}=8\sqrt{6}$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-8\sqrt{6}}{2*1}=\frac{14-8\sqrt{6}}{2}
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+8\sqrt{6}}{2*1}=\frac{14+8\sqrt{6}}{2}
$