X^2-16x-7=-5

Solution for X^2-16x-7=-5 equation:

X^2-16X-7=-5

We move all terms to the left:

X^2-16X-7-(-5)=0

We add all the numbers together, and all the variables

X^2-16X-2=0

a = 1; b = -16; c = -2;
Δ = b2-4ac
Δ = -162-4·1·(-2)
Δ = 264
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{264}=\sqrt{4*66}=\sqrt{4}*\sqrt{66}=2\sqrt{66}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-2\sqrt{66}}{2*1}=\frac{16-2\sqrt{66}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+2\sqrt{66}}{2*1}=\frac{16+2\sqrt{66}}{2}
$