(n+2)(7n+1)=0

Solution for (n+2)(7n+1)=0 equation:

(n+2)(7n+1)=0

We multiply parentheses ..

(+7n^2+n+14n+2)=0

We get rid of parentheses

7n^2+n+14n+2=0

We add all the numbers together, and all the variables

7n^2+15n+2=0

a = 7; b = 15; c = +2;
Δ = b2-4ac
Δ = 152-4·7·2
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-13}{2*7}=\frac{-28}{14}
=-2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+13}{2*7}=\frac{-2}{14}
=-1/7
$