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Undue Obsession II

Okay I just did it my way and it works much better.

         7x + 7y = 8x - 8y
         8x - 7x = 7y + 8y
               x = 15y
Plug into first eq:
     7(15y) + 7y = 5432
       105y + 7y = 5432
            112y = 5432
               y = 48.5
And then you'd continue from here to get the speed of the aircraft in still air.

The key is that the two original equations are equal to the same constant. When I put them together to get rid of that constant in the first line of this solution, I was in effect doing the adding and subtracting of the two lines of the previous solution in one fell swoop.

So, then my question is, WHY THE HELL DOES THE SCHOOL CURRICULUM TEACH KIDS HOW TO DO THINGS THE STUPID WAY?!?!?!?!

Particularly when it really doesn't make any sense. It's not easier to understand and it requires a leap of faith that it will work out. In my solution, you can actually see what's going on with the x's and y's and all the laws of Math symbols are preserved.

Comments

ntang
Oct. 20th, 2001 12:22 pm (UTC)
Actually your way seems pretty non-intuitive to me too.

Read my last comment, on the original post, and tell me what you think.

(I realize it's the same basic thing, just put into a formula, but my way I think could be explained to a 12 year old and I actually had to think about yours for a few minutes to realize you were saying the same basic thing.)
bride
Oct. 20th, 2001 12:53 pm (UTC)
No formula here. It's a categorical syllogism: A equals C and B also equals C, so A is equal to B.
      7x + 7y = 5432
      8x - 8y = 5432
So:   7x + 7y = 8x - 8y

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eLouai
bride
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