6x+x(x-8)=59

Solution for 6x+x(x-8)=59 equation:

6x+x(x-8)=59

We move all terms to the left:

6x+x(x-8)-(59)=0

We multiply parentheses

x^2+6x-8x-59=0

We add all the numbers together, and all the variables

x^2-2x-59=0

a = 1; b = -2; c = -59;
Δ = b2-4ac
Δ = -22-4·1·(-59)
Δ = 240
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:

$\sqrt{\Delta}=\sqrt{240}=\sqrt{16*15}=\sqrt{16}*\sqrt{15}=4\sqrt{15}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-4\sqrt{15}}{2*1}=\frac{2-4\sqrt{15}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+4\sqrt{15}}{2*1}=\frac{2+4\sqrt{15}}{2}
$