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

Solution for 36-(2x+7)(2x+7)=0 equation:

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

We multiply parentheses ..

-(+4x^2+14x+14x+49)+36=0

We get rid of parentheses

-4x^2-14x-14x-49+36=0

We add all the numbers together, and all the variables

-4x^2-28x-13=0

a = -4; b = -28; c = -13;
Δ = b2-4ac
Δ = -282-4·(-4)·(-13)
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*-4}=\frac{4}{-8}
=-1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+24}{2*-4}=\frac{52}{-8}
=-6+1/2
$