A vending 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

112 bags of chips

The solution to the system of equations gives 112 chips and 216 candy.

The equations to solve are

x + y = 328

.40x +.50 y = 152.80

(x = the number of chips and y = the number of candy)