28x^2-14x-14=0

Solution for 28x^2-14x-14=0 equation:

28x^2-14x-14=0

a = 28; b = -14; c = -14;
Δ = b2-4ac
Δ = -142-4·28·(-14)
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-42}{2*28}=\frac{-28}{56}
=-1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+42}{2*28}=\frac{56}{56}
=1
$