28x^2-2x-6=0

Solution for 28x^2-2x-6=0 equation:

28x^2-2x-6=0

a = 28; b = -2; c = -6;
Δ = b2-4ac
Δ = -22-4·28·(-6)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-26}{2*28}=\frac{-24}{56}
=-3/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+26}{2*28}=\frac{28}{56}
=1/2
$