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

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

(X-5)(10+10X)=0

We add all the numbers together, and all the variables

(X-5)(10X+10)=0

We multiply parentheses ..

(+10X^2+10X-50X-50)=0

We get rid of parentheses

10X^2+10X-50X-50=0

We add all the numbers together, and all the variables

10X^2-40X-50=0

a = 10; b = -40; c = -50;
Δ = b2-4ac
Δ = -402-4·10·(-50)
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-60}{2*10}=\frac{-20}{20}
=-1
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+60}{2*10}=\frac{100}{20}
=5
$