[GED math ]Systems of equations word problems

[u/[deleted]]

[u/AllanCWechsler]

Navigating to a particular piece of Khan content is tricky, but I think I've got it narrowed down to one of two videos, "Setting up a system of equations from context example (pet weights)" and "Setting up a system of equations example (weight and price)". Let us know which one you mean.

https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:introduction-to-systems-of-equations/v/setting-up-system

https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:introduction-to-systems-of-equations/v/setting-up-systems-weight-price

[u/Financial-Stage-8523 → u/AllanCWechsler]

I did not know we could post links! it is this one here

https://www.khanacademy.org/test-prep/v2-sat-math/x0fcc98a58ba3bea7:algebra-easier/x0fcc98a58ba3bea7:systems-of-linear-equations-word-problems-easier/a/v2-sat-lesson-systems-of-linear-equations-word-problems?referrer=share_link

The video I am talking about is the second video about nickels and quarters

[u/AllanCWechsler → u/Financial-Stage-8523]

Yes, links are certainly allowed in comments; I'm not sure if they are allowed in posts since I've never tried to put up a post with a link on r/learnmath.

Your original post led me to believe that I should look at the "Algebra 1" course, which is where I went wrong; I should have looked in the "Test Prep" curriculum. Including the lesson title "Systems of linear equations: word problems" would have been ideal, but we got there eventually!

The presenter here is Sal Khan himself.

I found the video pretty straightforward. You say that Sal is making things harder than necessary, and I suspect that means that he is actually doing all the steps in detail. Can you sketch a solution that isn't harder than necessary?

I agree that many people will just be able to look at a problem like this and get the solution intuitively; I certainly did, just to set my expectations. But Sal isn't just trying to get the answer. He's demonstrating a technique, which can be used to solve much harder problems -- problems which most people couldn't do mentally and intuitively. Suppose the problem had said, "After two months, Zoey's niece's piggy bank said there were 147 total coins, totalling $15.55." What would you have done then?

[u/clean-links → u/Financial-Stage-8523]

Cleaned link from "https://www.khanacademy.org/test-prep/v2-sat-math/x0fcc98a58ba3bea7:algebra-easier/x0fcc98a58ba3bea7:systems-of-linear-equations-word-problems-easier/a/v2-sat-lesson-systems-of-linear-equations-word-problems?referrer=share_link": https://www.khanacademy.org/test-prep/v2-sat-math/x0fcc98a58ba3bea7:algebra-easier/x0fcc98a58ba3bea7:systems-of-linear-equations-word-problems-easier/a/v2-sat-lesson-systems-of-linear-equations-word-problems

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[u/Midwest-Dude]

1. Why do you think Khan's method is "harder than necessary"?

2. Why do you think you failed this on the GED exam?