Final answer:
The set {0,1,2,3,4,5...} can be represented in set-builder notation as x is a natural number and x is greater than or equal to 0.
Step-by-step explanation:
The set {0,1,2,3,4,5...} represents the set of natural numbers starting from 0 and going up indefinitely. In set-builder notation, it can be written as x is a natural number and x is greater than or equal to 0.