The sum of twice a number and seven is twenty five

Can someone me and do the problem plz so i can understand it more better

Question: a) does the given set of points represent a linear function? how do you know? b) assume that the point (-2,4) lies on the graph of a line. what y-values could complete this set of ordered pairs that lie on the same line: (- (hint: there are several correct answ

Is this a polynomial function? i need to know asap