Is there a shorter way to calculate the 8th power of the product in the parentheses if I decide to use the strategy in the second note? Or will I have to multiply 8 times on the calculator?

Square it four times.

The calculator does not have a square function?

No, but it does have a memory function. So you can save the result of x^{2} (or anything else) and easily retrieve it.

Fantastic idea