How to display verbatim inline r code with backticks using Rmarkdown?

Question

By doubling the backticks in Markdown, it is easy to render some text in code style including the backticks, such as: `r 2+2`. But how to do that with RMark

Answer 1

The solution of Yihui Xie was not displaying the enclosing quotations in the inserted code when rendering a README.md file for a Github repository. In that case I used html code:

`r foo(x)`

Which displays `r foo(x)` inline.