(8x-48)(5x+35)=0

Solution for (8x-48)(5x+35)=0 equation:

(8x-48)(5x+35)=0

We multiply parentheses ..

(+40x^2+280x-240x-1680)=0

We get rid of parentheses

40x^2+280x-240x-1680=0

We add all the numbers together, and all the variables

40x^2+40x-1680=0

a = 40; b = 40; c = -1680;
Δ = b2-4ac
Δ = 402-4·40·(-1680)
Δ = 270400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{270400}=520$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-520}{2*40}=\frac{-560}{80}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+520}{2*40}=\frac{480}{80}
=6
$