X+2+x+9+x2=180

Solution for X+2+x+9+x2=180 equation:

X+2+X+9+X2=180

We move all terms to the left:

X+2+X+9+X2-(180)=0

We add all the numbers together, and all the variables

X^2+2X-169=0

a = 1; b = 2; c = -169;
Δ = b2-4ac
Δ = 22-4·1·(-169)
Δ = 680
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:

$\sqrt{\Delta}=\sqrt{680}=\sqrt{4*170}=\sqrt{4}*\sqrt{170}=2\sqrt{170}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{170}}{2*1}=\frac{-2-2\sqrt{170}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{170}}{2*1}=\frac{-2+2\sqrt{170}}{2}
$