(7s+1)(s+1)=0

Solution for (7s+1)(s+1)=0 equation:

(7s+1)(s+1)=0

We multiply parentheses ..

(+7s^2+7s+s+1)=0

We get rid of parentheses

7s^2+7s+s+1=0

We add all the numbers together, and all the variables

7s^2+8s+1=0

a = 7; b = 8; c = +1;
Δ = b2-4ac
Δ = 82-4·7·1
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-6}{2*7}=\frac{-14}{14}
=-1
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+6}{2*7}=\frac{-2}{14}
=-1/7
$