(x)=x^2-16

Solution for (x)=x^2-16 equation:

(x)=x^2-16

We move all terms to the left:

(x)-(x^2-16)=0

We get rid of parentheses

-x^2+x+16=0

We add all the numbers together, and all the variables

-1x^2+x+16=0

a = -1; b = 1; c = +16;
Δ = b2-4ac
Δ = 12-4·(-1)·16
Δ = 65
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{-(1)-\sqrt{65}}{2*-1}=\frac{-1-\sqrt{65}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{65}}{2*-1}=\frac{-1+\sqrt{65}}{-2}
$