18. find the inverse of {(4, -1), (3, -2), (6, 9), (8, 5)}.

f. {(8, 5), (6, 9), (3, -2), (4, -1)}

h. {(-1, 4), (-2, 3), (9, 6), (5, 8)}

g. {(-4, 1), (-3, 2), (-6, -9), (-8, -5)}

j. {(-1, -2), (9, 5), (4, 3), (6, 8)} 19.

19.
if f (x) = 3x - 4, find f -1 (x).

a f -1 (x) = 4x - 3 b f -1 (x) = − x + 4 3 c f -1 (x) = − x - 4 3

d f -1 (x) = -4 - 3x 20. if f (x) = 8(5x - 2), find f -1 (x).

f f -1 (x) = − 5x + 2 8 g f -1 (x) = − 5x - 2 8 h f -1 (x) = − x - 16 40

j f -1 (x) = −