SOLUTION: Helping daughter with homework and my memory has gone. This is probably pretty easy but I just need the rule when working these out so here goes - 2b^3 with b=4, I had gone for

You are confusing  with .
You would have been right if it had those parentheses.
But it doesn't.

Parentheses are very important in algebra.
When you put in parentheses an expression will
very often mean something entirely different.

ONLY the  gets raised to the 3rd power.

The  does not get raised to the third power because
it is not inside parentheses with the 






Edwin