8(x+15)(x+3)=0

Solution for 8(x+15)(x+3)=0 equation:

8(x+15)(x+3)=0

We multiply parentheses ..

8(+x^2+3x+15x+45)=0

We multiply parentheses

8x^2+24x+120x+360=0

We add all the numbers together, and all the variables

8x^2+144x+360=0

a = 8; b = 144; c = +360;
Δ = b2-4ac
Δ = 1442-4·8·360
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{-(144)-96}{2*8}=\frac{-240}{16}
=-15
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(144)+96}{2*8}=\frac{-48}{16}
=-3
$