15x(2)+6x-9(2)=360

Solution for 15x(2)+6x-9(2)=360 equation:

15x(2)+6x-9(2)=360

We move all terms to the left:

15x(2)+6x-9(2)-(360)=0

We add all the numbers together, and all the variables

15x^2+6x-452=0

a = 15; b = 6; c = -452;
Δ = b2-4ac
Δ = 62-4·15·(-452)
Δ = 27156
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:

$\sqrt{\Delta}=\sqrt{27156}=\sqrt{4*6789}=\sqrt{4}*\sqrt{6789}=2\sqrt{6789}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-2\sqrt{6789}}{2*15}=\frac{-6-2\sqrt{6789}}{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+2\sqrt{6789}}{2*15}=\frac{-6+2\sqrt{6789}}{30}
$