PLEASE HELP ASAP

Sandra is a bus driver who also raises turkey for supplemental income. She is trying to decide what to feed her turkeys. She is considering using a combination of turkey feeds available from local suppliers. She would like to feed the turkeys at minimum cost while also making sure each turkey receives a daily adequate supply of calories and vitamins. Sandra has formulated the following Linear Programming (LP) model:

Let X1 = pounds of Feed Type 1 in diet X2 = pounds of Feed Type 2 in diet Minimize Z = $0.3X1 + $0.5X2 (Cost) subject to

1. 800X1 + 1,000X2 8,000 (requirement of calories per day)
2. 140X1 + 70X2 700 (requirement of units of vitamins)
3. X1 (1/3)(X1 + X2) (constraint 3)
4. X1 0, X2 0.

1. Briefly explain or define the 140 units in the vitamins constraint. (2 points)