PLEASE HELP ME! Khan Academy Algebra 1

Question

Marcelina uses a blend of white corn and yellow corn to make tortilla chips at her restaurant. She needs to buy 50kg of corn in total for her next order. White corn costs $0.30 per kilogram, yellow corn costs $0.15 per kilogram, and she wants to spend $12 total. Here's a graph that shows a system of equations for this scenario where x is the amount of white corn she buys and y is the amount of yellow corn she buys. Point C is on line A and above line B. What does point C represent in this context?

Answer 1

Hi Aa D.,

So one of your lines is probably slope -1 and represents the relationship between amount of white and yellow corn to comprise 50 kg total.

I'm guessing that the other line is an iso-cost plot for $12, and has slope either -2 or -(1/2) depending on which axis is your yellow corn. You can interpret the position of C, based on which line it's on. I'm guessing it's on the slope -1 line; being above the other line would represent spending more than $12, therefore (the region to (x,y)=(+,+) is high cost, obviously?).

Now the problem gets interesting! WHY does she attempt to meet a particular cost; why not make pure yellow-corn tortilla chips? What is the anticipated (or, actual in your own experience) difference in nutrition, flavor or public demand for/in yellow vs. white corn? You need to read up the process of nixtamalization (lime treatment), perhaps, which removes carcinogenic aflatoxins, and liberates niacin and tryptophane. Don't bother with se, su, and sh2 genomic stuff, that's for corn-on-the-cob usage. It's all fascinating stuff!

--Cheers, --Mr. d.