Can somebody tell me why this command doesn't work?

Question

$\frac{1-(-$\frac{1}{2}^t$) }{$\frac{3}{2}$}$

For some reason it gives me an error, something about a Missing \endgroup, be warned I'm new to Latex.

Answer 1

You are using too many $ and hence forcing tex to enter math mode when it is already in math mode. Hence remove all internal $. Also the super script t should go outside the parenthesis. Assuming that you are in display mode, I have added \displaystyle. If not, remove it and also \big.

\documentclass{article}
\usepackage{mathtools}
\begin{document}
$\displaystyle \frac{1-\big(-\frac{1}{2}\big)^t}{\frac{3}{2}}$
\end{document}

Answer 2

Remove inner $.

$\frac{1-(-\frac{1}{2}^t)}{\frac{3}{2}}$

should do the trick. The following is just a suggestion:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
$\dfrac{1-\left(-\frac{1}{2}^t\right)}{\frac{3}{2}}$
\end{document}