9x^2+8x-240=0

Solution for 9x^2+8x-240=0 equation:

9x^2+8x-240=0

a = 9; b = 8; c = -240;
Δ = b2-4ac
Δ = 82-4·9·(-240)
Δ = 8704
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:

$\sqrt{\Delta}=\sqrt{8704}=\sqrt{256*34}=\sqrt{256}*\sqrt{34}=16\sqrt{34}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-16\sqrt{34}}{2*9}=\frac{-8-16\sqrt{34}}{18}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+16\sqrt{34}}{2*9}=\frac{-8+16\sqrt{34}}{18}
$