Answer: No
Reason:
The friend should have multiplied the exponents.
This is what the steps should look like:
[tex](r^6)^4 = r^{6*4}\\\mbox{ \ \ \ \ \ \ } =r^{24}[/tex]
The reason for the multiplication is because we have four copies of [tex]r^4[/tex] added together. Repeated addition can be shortened to multiplication.
In other words,
[tex](r^6)^4 = (r^6)*(r^6)*(r^6)*(r^6) = r^{6+6+6+6} = r^{6*4} = r^{24}[/tex]
