When to use sample vs population standard deviation

The transitive property of equality states that: o if a = b, then bra o if a = b, then ac = bc o if a = b and b= c, then a = if a = b and c= c, then a + b = b + c

The tuition costs, c, for a local community college are modeled by c(h) = 250 + 200h, where h represents the number of credit hours taken. the local state university has tuition costs, s, modeled by the function s(h) = 300 + 180h. how many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

2/3(-6y+9x) expand each expression using the distributive property