x^2-10x=155

Solution for x^2-10x=155 equation:

x^2-10x=155

We move all terms to the left:

x^2-10x-(155)=0

a = 1; b = -10; c = -155;
Δ = b2-4ac
Δ = -102-4·1·(-155)
Δ = 720
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:

$\sqrt{\Delta}=\sqrt{720}=\sqrt{144*5}=\sqrt{144}*\sqrt{5}=12\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-12\sqrt{5}}{2*1}=\frac{10-12\sqrt{5}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+12\sqrt{5}}{2*1}=\frac{10+12\sqrt{5}}{2}
$