(7k+8)(k+6)=0

Solution for (7k+8)(k+6)=0 equation:

(7k+8)(k+6)=0

We multiply parentheses ..

(+7k^2+42k+8k+48)=0

We get rid of parentheses

7k^2+42k+8k+48=0

We add all the numbers together, and all the variables

7k^2+50k+48=0

a = 7; b = 50; c = +48;
Δ = b2-4ac
Δ = 502-4·7·48
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(50)-34}{2*7}=\frac{-84}{14}
=-6
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(50)+34}{2*7}=\frac{-16}{14}
=-1+1/7
$