Solve this using ALGEBRA! | Solving Systems of Linear Equations by Substitution

This video shows you one way you can solve this popular puzzle that has been floating around the internet. This method will work every time, and there is no guessing and checking! Comment below another way you could solve this problem.
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[@willjohnston2959]

Your presentation has the advantage of finding each animal's weight, and I like how you include a check to confirm each of the three original equations are true for your solution values. It might be worth discussing whether it's necessary to get each animal's weight when the original question doesn't ask for that. Since the question asks for sum of animals' weights, you might also see you can combine the three given equations by adding. You get 2D + 2C + 2R = 54 From that you can say D + C + R must simply be 1/2 of 54, or 27. You get the answer even without knowing any animal's weight. Perhaps students can reflect on the advantages and disadvantages of the different approaches.

[@homemademathematics]

Yes!!! I love this approach! Another teacher shared that strategy with me over on my Facebook page and it was so cool to see the various different ways you can solve! Definitely a conversation starter!