x2+2x+2x-30=75

Solution for x2+2x+2x-30=75 equation:

x2+2x+2x-30=75

We move all terms to the left:

x2+2x+2x-30-(75)=0

We add all the numbers together, and all the variables

x^2+4x-105=0

a = 1; b = 4; c = -105;
Δ = b2-4ac
Δ = 42-4·1·(-105)
Δ = 436
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:

$\sqrt{\Delta}=\sqrt{436}=\sqrt{4*109}=\sqrt{4}*\sqrt{109}=2\sqrt{109}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-2\sqrt{109}}{2*1}=\frac{-4-2\sqrt{109}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+2\sqrt{109}}{2*1}=\frac{-4+2\sqrt{109}}{2}
$