7x2-72x-144=0

Solution for 7x2-72x-144=0 equation:

7x^2-72x-144=0

a = 7; b = -72; c = -144;
Δ = b2-4ac
Δ = -722-4·7·(-144)
Δ = 9216
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9216}=96$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-72)-96}{2*7}=\frac{-24}{14}
=-1+5/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-72)+96}{2*7}=\frac{168}{14}
=12
$