4. Slope Price of Novels △y 13$8 8 △x 6-8=-2 21$6 6 21-13=8 0 5 13 17 21 25 Quantity of Novels Purchased sop 1y first y-coordinate -second y-coordinate 21-1384 first x-coordinate-second x-coordinate4. Slope 0 2 4 6 8 1 0 1 2 0 5 9 1 3 1 7 2 1 2 5 Price of Novels Quantity of Novels Purchased 13,$8 6-8=-2 21,$6 21-13=8 x y slo p   = 4 1 8 2 2 1 1 3 6 8 − = − = − − = =   = firstyco o rdin atea a a aaaaaaaaaaa aaaaaaaaaa aaaaa x y slo p first y-coordinate – second y-coordinate first x-coordinate – second x-coordinate