(3x+7)(2x-5)(8)=0

Solution for (3x+7)(2x-5)(8)=0 equation:

(3x+7)(2x-5)(8)=0

We multiply parentheses ..

(+6x^2-15x+14x-35)8=0

We multiply parentheses

48x^2-120x+112x-280=0

We add all the numbers together, and all the variables

48x^2-8x-280=0

a = 48; b = -8; c = -280;
Δ = b2-4ac
Δ = -82-4·48·(-280)
Δ = 53824
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{53824}=232$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-232}{2*48}=\frac{-224}{96}
=-2+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+232}{2*48}=\frac{240}{96}
=2+1/2
$