2(x-1)(x+5)=0

Solution for 2(x-1)(x+5)=0 equation:

2(x-1)(x+5)=0

We multiply parentheses ..

2(+x^2+5x-1x-5)=0

We multiply parentheses

2x^2+10x-2x-10=0

We add all the numbers together, and all the variables

2x^2+8x-10=0

a = 2; b = 8; c = -10;
Δ = b2-4ac
Δ = 82-4·2·(-10)
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-12}{2*2}=\frac{-20}{4}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+12}{2*2}=\frac{4}{4}
=1
$