9x^2-62x-72=0

Solution for 9x^2-62x-72=0 equation:

9x^2-62x-72=0

a = 9; b = -62; c = -72;
Δ = b2-4ac
Δ = -622-4·9·(-72)
Δ = 6436
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:

$\sqrt{\Delta}=\sqrt{6436}=\sqrt{4*1609}=\sqrt{4}*\sqrt{1609}=2\sqrt{1609}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-62)-2\sqrt{1609}}{2*9}=\frac{62-2\sqrt{1609}}{18}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-62)+2\sqrt{1609}}{2*9}=\frac{62+2\sqrt{1609}}{18}
$