-7x(x-7)=-36

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

-7x(x-7)=-36

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We multiply parentheses

-7x^2+49x+36=0

a = -7; b = 49; c = +36;
Δ = b2-4ac
Δ = 492-4·(-7)·36
Δ = 3409
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(49)-\sqrt{3409}}{2*-7}=\frac{-49-\sqrt{3409}}{-14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(49)+\sqrt{3409}}{2*-7}=\frac{-49+\sqrt{3409}}{-14}
$