Maths homework- help!

[Notagoodtime]

Ds is in trouble for not completing his homework. I’m trying to help him but stumped on the one. Anyone up who can help please ?

It's a common GCSE question, usually on the non-calculator paper. A really quick and easy one if special powers have been learnt revised and the first four or five powers of 2.3.5, maybe 4 have been learnt.