14x^2-20=66x

Solution for 14x^2-20=66x equation:

14x^2-20=66x

We move all terms to the left:

14x^2-20-(66x)=0

a = 14; b = -66; c = -20;
Δ = b2-4ac
Δ = -662-4·14·(-20)
Δ = 5476
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5476}=74$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-66)-74}{2*14}=\frac{-8}{28}
=-2/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-66)+74}{2*14}=\frac{140}{28}
=5
$