can you use x on a scientific calculator

well the web2 calc will solve equations for you.

e.g

 

i enter

x^2-7=8             And the calc gives me the answer.  Isn't that nifty :)

 

$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{7}} = {\mathtt{8}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\sqrt{{\mathtt{15}}}}\\
{\mathtt{x}} = {\sqrt{{\mathtt{15}}}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{3.872\: \!983\: \!346\: \!207\: \!416\: \!9}}\\
{\mathtt{x}} = {\mathtt{3.872\: \!983\: \!346\: \!207\: \!416\: \!9}}\\
\end{array} \right\}$$