0=-x^2+x+16

Solution for 0=-x^2+x+16 equation:

0=-x^2+x+16

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We get rid of parentheses

x^2-x-16=0

We add all the numbers together, and all the variables

x^2-1x-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}
$