(2n+8)(7n+35)=0

Solution for (2n+8)(7n+35)=0 equation:

(2n+8)(7n+35)=0

We multiply parentheses ..

(+14n^2+70n+56n+280)=0

We get rid of parentheses

14n^2+70n+56n+280=0

We add all the numbers together, and all the variables

14n^2+126n+280=0

a = 14; b = 126; c = +280;
Δ = b2-4ac
Δ = 1262-4·14·280
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(126)-14}{2*14}=\frac{-140}{28}
=-5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(126)+14}{2*14}=\frac{-112}{28}
=-4
$