x(x-5)=76

Solution for x(x-5)=76 equation:

x(x-5)=76

We move all terms to the left:

x(x-5)-(76)=0

We multiply parentheses

x^2-5x-76=0

a = 1; b = -5; c = -76;
Δ = b2-4ac
Δ = -52-4·1·(-76)
Δ = 329
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-\sqrt{329}}{2*1}=\frac{5-\sqrt{329}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+\sqrt{329}}{2*1}=\frac{5+\sqrt{329}}{2}
$