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# Systems of equations: trolls, tolls (1 of 2)

A troll forces us to use algebra to figure out the make-up of his currency. We end up setting up a system of equations. Created by Sal Khan.

## Want to join the conversation?

• Is it possible to solve this problem using the computer science software on Khan Academy?
• It is possible, although Sal's method is by far the easiest.
• Are there other ways to solves these types of equations?
• And there are other ways too, that look different, and use different specific steps, but are ultimately "equivalent" to the above. Matrix Inversion is one such example. That comes with "Linear Algebra", a more advanced topic. The beauty of using matrices to represent your set of linear equations is how well it lends itself to solutions by machine (as opposed to "by hand").
• The troll at the end: Thanks bro I really needed someone to count my loot for me
• I guess to the troll is moved by the action of the human rescuing someone because the troll gave the human 1 extra minute. Did anyone notice that? 😂
• Is it possible to have multiple equations in a system of equations? Could I have, say, 4 different equations?
• Yes you could. There are later missions that you have to use 2 different system of equations.
• How would you use this in real life (besides solving riddles to save princesses lol)
• you can use this for lots of stuff. like with the coffee beans, finding how many pounds you can buy at a certain price, or with different cell service companies for comparing rates and finding out which one is cheaper at certain points.
• Does this tie into systems of inequalities?
• Are there any tips on how to write systems of equations and getting them correct? I get confused on how to write them at times. Is there a way that helps a lot?
• The main thing is just to concentrate and practice. And yes, looking at the word "practice" might bore you, but it doesn't lie. That's really the only way to get your answers correct, by practicing similar questions. Look up more tutorials or ask someone to test you on your knowledge.