4n+8n(2)=140

Solution for 4n+8n(2)=140 equation:

4n+8n(2)=140

We move all terms to the left:

4n+8n(2)-(140)=0

We add all the numbers together, and all the variables

8n^2+4n-140=0

a = 8; b = 4; c = -140;
Δ = b2-4ac
Δ = 42-4·8·(-140)
Δ = 4496
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4496}=\sqrt{16*281}=\sqrt{16}*\sqrt{281}=4\sqrt{281}$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-4\sqrt{281}}{2*8}=\frac{-4-4\sqrt{281}}{16}
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+4\sqrt{281}}{2*8}=\frac{-4+4\sqrt{281}}{16}
$