To simplify the terms you execute a prime factorization (divide exactly by the smallest prime possible until you reach 1) which in the case of 320 would be: 320=2*2*2*2*2*2*5. Every factor which exists twice can be taken out of the root. Simplify the many 2s into 2 equal readable factors: 320=2*2*2*2*2*2*5=8*8*5
and the end