Avending machine sells chips at $0.40 and candy at $0.50. last month, the vending machine yielded $152.80 with a sale of 328 items. how many packages of chips were purchased last month

X = 40 cents bags, y = 50 cent bags

x + y = 328...x = 328 - y
0.40x + 0.50y = 152.80

0.40(328 - y) + 0.50y = 152.80
131.20 - 0.40y + 0.50y = 152.80
-0.40y + 0.50y = 152.80 - 131.20
0.10y = 21.60
y = 21.60/0.10
y = 216 <=== total 50 cents bags sold

x + y = 328
x + 216 = 328
x = 328 - 216
x = 112 <=== total 40 cents bags sold