Originally Posted by

**earboth** With Jonboy's method you can use different colours to cross out different terms.

It would be nice and much more legible if the horizontal line could be printed in bold style. Unfortunately I didn't find the appropriate command

. The \bold{..} obviously only works with numbers and letters.

Using \vrule, you can create lines of any height, depth and width that you want. For example, comes from this code:

Code:

\frac{(\rlap{\color{red}\vrule height3.5pt depth-2pt width2.3em}
x + 5)(x - 2) (\rlap{\color{blue}\vrule height3.5pt depth-2pt width2.3em}
x + 7)}{(\rlap{\color{red}\vrule height3.5pt depth-2pt width2.3em}
x + 5) (\rlap{\color{blue}\vrule height3.5pt depth-2pt width2.3em}
x + 7)} = x - 2