This is not duplicated.
I know how to use the $ sign, but I want to write long equations and words after in the same line and I don't know how.
For example if I write:
$2=1+1=2(0.5+0.5)=\sum_{n=1}^40.5=\sum_{n=1}^21$this is happening
I can't use the $$ because this will split the output to two different lines.
How can I do that?