3(2n–4)– 1 4 n= 3 4 (n+4) n=

When written out in a string, your expression is:

 $3(2n–4)– 1 4 n= 3 4 (n+4) n$

$6n-12-14n=34n^2+136n$

$34n^2+144n+12=0$

$17n^2+72n+6=0$

$n = {-72 \pm \sqrt{72^2-4\cdot17\cdot6} \over 34} \space \text{(Using the quadratic formula)}$

$n=\frac{-72 \pm \sqrt{4776}}{34}$

$n=\frac{-72 \pm 2\sqrt{1194}}{34}$

$n=\frac{-36 \pm \sqrt{1194}}{17}$

Which is as simple as we can get it.