l*(l-5)=134

Solution for l*(l-5)=134 equation:

l(l-5)=134

We move all terms to the left:

l(l-5)-(134)=0

We multiply parentheses

l^2-5l-134=0

a = 1; b = -5; c = -134;
Δ = b2-4ac
Δ = -52-4·1·(-134)
Δ = 561
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$l_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$l_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$l_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-\sqrt{561}}{2*1}=\frac{5-\sqrt{561}}{2}
$
$l_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+\sqrt{561}}{2*1}=\frac{5+\sqrt{561}}{2}
$