Which of the sets of ordered pairs represents a function?
a = {(2, −2), (5, −5), (−2, 2), (−5, 5)}
b = {(4, 2), (4, −2), (9, 3), (9, −3)}
only a
only b
both a and b
neither a nor b

Will mark 50 show all what is the solution to the system of equations? use the substitution method and show your work. -5x+y= -3 -15 x+3y=7 explain what your answer in part (a) tells you about the association of the lines in this system.