(5x-10)*(5x+3)=0

Solution for (5x-10)*(5x+3)=0 equation:

(5x-10)(5x+3)=0

We multiply parentheses ..

(+25x^2+15x-50x-30)=0

We get rid of parentheses

25x^2+15x-50x-30=0

We add all the numbers together, and all the variables

25x^2-35x-30=0

a = 25; b = -35; c = -30;
Δ = b2-4ac
Δ = -352-4·25·(-30)
Δ = 4225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4225}=65$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-35)-65}{2*25}=\frac{-30}{50}
=-3/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-35)+65}{2*25}=\frac{100}{50}
=2
$