(x+7)(2x+2)=0

Solution for (x+7)(2x+2)=0 equation:

(x+7)(2x+2)=0

We multiply parentheses ..

(+2x^2+2x+14x+14)=0

We get rid of parentheses

2x^2+2x+14x+14=0

We add all the numbers together, and all the variables

2x^2+16x+14=0

a = 2; b = 16; c = +14;
Δ = b2-4ac
Δ = 162-4·2·14
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{-(16)-12}{2*2}=\frac{-28}{4}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+12}{2*2}=\frac{-4}{4}
=-1
$