Anybody know this ??

Which of the following contains a variable?

Find the domain and range of the following function f(x) = 51x - 21+ 4

50 people men and women were asked if they watched at least one sport on tv. 20 of the people surveyed are women, but only 9 of them watch at least one sport on tv. 16 of the men watch at least one sport on tv. make a a two-way table and a relative frequency table to represent the data.