(7x+19)(3x-255)=0

Solution for (7x+19)(3x-255)=0 equation:

(7x+19)(3x-255)=0

We multiply parentheses ..

(+21x^2-1785x+57x-4845)=0

We get rid of parentheses

21x^2-1785x+57x-4845=0

We add all the numbers together, and all the variables

21x^2-1728x-4845=0

a = 21; b = -1728; c = -4845;
Δ = b2-4ac
Δ = -17282-4·21·(-4845)
Δ = 3392964
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3392964}=1842$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1728)-1842}{2*21}=\frac{-114}{42}
=-2+5/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1728)+1842}{2*21}=\frac{3570}{42}
=85
$