markdown affecting asterisk usage in code examples

[gwurbo]

I started noticing this around chapter 6 - some code using powers and multiplication will be bolded or italicized instead.

Example from Chapter 6 - 3D Surface Plots. Instead of showing the double asterisks for power, it is bolded.

Example from Chapter 7 - Functions with Multiple Arguments. Instead of the asterisks showing multiplication, it is italicized.