(b-10)(b+10)=360

Solution for (b-10)(b+10)=360 equation:

(b-10)(b+10)=360

We move all terms to the left:

(b-10)(b+10)-(360)=0

We use the square of the difference formula

b^2-100-360=0

We add all the numbers together, and all the variables

b^2-460=0

a = 1; b = 0; c = -460;
Δ = b2-4ac
Δ = 02-4·1·(-460)
Δ = 1840
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1840}=\sqrt{16*115}=\sqrt{16}*\sqrt{115}=4\sqrt{115}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{115}}{2*1}=\frac{0-4\sqrt{115}}{2}
=-\frac{4\sqrt{115}}{2}
=-2\sqrt{115}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{115}}{2*1}=\frac{0+4\sqrt{115}}{2}
=\frac{4\sqrt{115}}{2}
=2\sqrt{115}
$