Question

$\begin{array}{c}12x^7+x^7+x=?\\ \text{if}x=8\end{array}$

Answer 1

$12x^7+x^7+x=?$ if $x=8$

$\Rightarrow 13x^7+x$

$\Rightarrow x[13x^6+1]$

$\Rightarrow 8\left[13\right(8{)}^6+1]$

$\Rightarrow 8\left[13\right(2^3{)}^6+1]$

$\Rightarrow 8\left[13\right(2{)}^{18}+1]$

$\Rightarrow 8\left[13\right(2^5{.2}^5{.2}^5{.2}^3)+1]$

$\Rightarrow 8\left[\right(13\times 32\times 32\times 32\times 8)+1]$

$\Rightarrow 27262984$