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

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

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

We multiply parentheses ..

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

We multiply parentheses

5x^2+10x+5x+10=0

We add all the numbers together, and all the variables

5x^2+15x+10=0

a = 5; b = 15; c = +10;
Δ = b2-4ac
Δ = 152-4·5·10
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-5}{2*5}=\frac{-20}{10}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+5}{2*5}=\frac{-10}{10}
=-1
$