Libre Office Calc Error 509

What am I doing wrong here please.?
error 509 when using: average=(A123:B156),(C300:D330)

I think I may have found the answer to the problem. If I am correct, then I have used brackets at the start and end of each set of references instead of at the start and end only.

The assumption in your comment is correct.

From the HELP:


Returns the average of the arguments.


AVERAGE(Number1; Number2; ...; Number30)

Number1, Number2, …, Number30 are
numerical values or ranges.

Thank you for the conformation that I messed up, I haven’t used a chart for many moons and forgot the correct syntax. That clears up this question and I thank robleyd for his answer.