Mathematics - Binomial Theorem Question with Solution | TestHub

$x^{15}-x^{13}+x^{11}-x^9+x^7-x^5+x^3-x$ $\begin{array}{rlrlr}& =x\left(x^8+1\right)\left(x^4+1\right)\left(x^2-1\right)& x^{16}-1=\left(x^8+1\right)\left(x^4+1\right)\left(x^2+1\right)\left(x^2-1\right)& =\frac{7}{x}\left(x^2+1\right)=7\left[{\left(\sqrt{x}-\frac{1}{\sqrt{x}}\right)}^2+2\right]>14& \therefore x^{16}>15\end{array}$