72x^2-69x-36=0

Solution for 72x^2-69x-36=0 equation:

72x^2-69x-36=0

a = 72; b = -69; c = -36;
Δ = b2-4ac
Δ = -692-4·72·(-36)
Δ = 15129
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{15129}=123$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-69)-123}{2*72}=\frac{-54}{144}
=-3/8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-69)+123}{2*72}=\frac{192}{144}
=1+1/3
$