Issue with fraction multiplication, everything being considered as being the denominator

Question

I am working in the Overleaf IDE, and simply trying to write down some fraction multiplications. As a simple example, let's consider the expression to be (a/b)(c/d).

Within my \begin{displaymath} environment, my code is this:

\frac{a}{b} \frac{c}{d}

Yet what comes out is a times (blank over b times (c over d)). Sorry if that's a confusing way of writing it. I've included a picture of the output. I've also tried writing the code with parentheses around the two fractions, but the same error occurs. I just want to write down some simple fractions, can anyone point out what might be causing this issue?

Answer 1

I would guess that you have

\documentclass{article}

\begin{document}

\begin{displaymath}
  
\frac{a}{b} \frac{c}{d}

\end{displaymath}
\end{document}

You need to remove the blank lines.

Never ignore errors, Latex reports

! Missing $ inserted.
<inserted text> 
                $
l.6 
    
? 

After any error the PDF is not intended to be usable. (a red circle on overleaf)