1 Which set of ordered pairs does not represent a function? 1 {(1, 10), (3, 18), (5, 26), (7, 34), (9, 42)
2 {(2, 10), (3, 20), (4, 15), (5,5), (6,25)
3 {(0,8), (5,4), (10,0), (15, 4), (20,8)
4 {(9, 1), (6,2), (3, 3), (6,4), (9,5)}

Can someone tell me if this is perpendicular? !

What is r i 4.5+10r=-6.5 with work pls

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?