x^2-9x-153=0

Solution for x^2-9x-153=0 equation:

x^2-9x-153=0

a = 1; b = -9; c = -153;
Δ = b2-4ac
Δ = -92-4·1·(-153)
Δ = 693
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:

$\sqrt{\Delta}=\sqrt{693}=\sqrt{9*77}=\sqrt{9}*\sqrt{77}=3\sqrt{77}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-3\sqrt{77}}{2*1}=\frac{9-3\sqrt{77}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+3\sqrt{77}}{2*1}=\frac{9+3\sqrt{77}}{2}
$