8105=x^2+10x+30

Solution for 8105=x^2+10x+30 equation:

8105=x^2+10x+30

We move all terms to the left:

8105-(x^2+10x+30)=0

We get rid of parentheses

-x^2-10x-30+8105=0

We add all the numbers together, and all the variables

-1x^2-10x+8075=0

a = -1; b = -10; c = +8075;
Δ = b2-4ac
Δ = -102-4·(-1)·8075
Δ = 32400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{32400}=180$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-180}{2*-1}=\frac{-170}{-2}
=+85
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+180}{2*-1}=\frac{190}{-2}
=-95
$