x2+2x=144

Solution for x2+2x=144 equation:

x2+2x=144

We move all terms to the left:

x2+2x-(144)=0

We add all the numbers together, and all the variables

x^2+2x-144=0

a = 1; b = 2; c = -144;
Δ = b2-4ac
Δ = 22-4·1·(-144)
Δ = 580
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:

$\sqrt{\Delta}=\sqrt{580}=\sqrt{4*145}=\sqrt{4}*\sqrt{145}=2\sqrt{145}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{145}}{2*1}=\frac{-2-2\sqrt{145}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{145}}{2*1}=\frac{-2+2\sqrt{145}}{2}
$