A function can't have x repeating any of the same number twice for example the first one (2, -2), (1, 5), (-2, 2), (1,-3), (8,-1) you have two 1's (1,5) and (1,-3) the x is the first number. Now a function can have the same y value. So your answer is (3, -1), (7,1), (-6,-1), (9,1), and (2,-1) you have to have all different x values in order for it to be a function. Hope that helps.
7/10-1/2 in simple form. so the two fractions have different denominators so you need to multiply both denominators 10x2 = 20 so both fractions have 20 on the bottom so they are like this now: 7/20-1/20= 6/20 simplify by 2: 6/20 divide by 2/2 =3/10. 3/10 is your answer