-p^2+8p-5=-9

Solution for -p^2+8p-5=-9 equation:

-p^2+8p-5=-9

We move all terms to the left:

-p^2+8p-5-(-9)=0

We add all the numbers together, and all the variables

-1p^2+8p+4=0

a = -1; b = 8; c = +4;
Δ = b2-4ac
Δ = 82-4·(-1)·4
Δ = 80
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{80}=\sqrt{16*5}=\sqrt{16}*\sqrt{5}=4\sqrt{5}$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-4\sqrt{5}}{2*-1}=\frac{-8-4\sqrt{5}}{-2}
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+4\sqrt{5}}{2*-1}=\frac{-8+4\sqrt{5}}{-2}
$