1/3 x 6 Please explain

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.

Ineed someone to me answer my question i have to have this done and knocked out