system software

there is an error in the question, it should be babaaa

../Regular Expressions] die a regular expression that enerates the language over the alphabet (a, b) whe ea's. For example, aaa and babaa are in the language llowed by exactly one or three a be alphabet (a, b) where each bin the string is followed by is not. (10 points) hur han Il strings of x's and y's where every y is immediately followed b) Write a regular expression for all string by at least three x's