-2x(x-7)=-36

Solution for -2x(x-7)=-36 equation:

-2x(x-7)=-36

We move all terms to the left:

-2x(x-7)-(-36)=0

We add all the numbers together, and all the variables

-2x(x-7)+36=0

We multiply parentheses

-2x^2+14x+36=0

a = -2; b = 14; c = +36;
Δ = b2-4ac
Δ = 142-4·(-2)·36
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-22}{2*-2}=\frac{-36}{-4}
=+9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+22}{2*-2}=\frac{8}{-4}
=-2
$