-2x(x-14)=26

Solution for -2x(x-14)=26 equation:

-2x(x-14)=26

We move all terms to the left:

-2x(x-14)-(26)=0

We multiply parentheses

-2x^2+28x-26=0

a = -2; b = 28; c = -26;
Δ = b2-4ac
Δ = 282-4·(-2)·(-26)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-24}{2*-2}=\frac{-52}{-4}
=+13
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+24}{2*-2}=\frac{-4}{-4}
=1
$