7n^2-168=-14n

Solution for 7n^2-168=-14n equation:

7n^2-168=-14n

We move all terms to the left:

7n^2-168-(-14n)=0

We get rid of parentheses

7n^2+14n-168=0

a = 7; b = 14; c = -168;
Δ = b2-4ac
Δ = 142-4·7·(-168)
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-70}{2*7}=\frac{-84}{14}
=-6
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+70}{2*7}=\frac{56}{14}
=4
$