How to use multiple isblank statements inside an if statement

=if(AND(isblank(g8),isblank(h8)), "both blank", "not both blank")

If your ranges are contiguous, using the following formula will take as many arguments as you want, with a much easier syntax to type when you expand the range:

=if(counta(g8:h8)=0, "both blank", "not both blank")