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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.


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.


( 9 comments — Leave a comment )
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.)
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
Oct. 20th, 2001 12:51 pm (UTC)
The schools also tend to teach kids the stupid way to read, the wrong way to write, and a lot of other bad ideas. I won't even get into how I feel about pointless "art" classes...

The more I see of the educational system, the more I really do think home schooling would be a better idea.

Oct. 20th, 2001 12:59 pm (UTC)
Home Schooling
You got _that_ right. I'm _seriously_ investigating other educational organizations for children. I see public education being a supplement to real education actually.

I'm disappointed at how blah I turned out and I want better for my children.
Oct. 20th, 2001 01:09 pm (UTC)
Re: Home Schooling
Blah? You're a regular testament to the fact that some people come out intelligent DESPITE what the schools did to them. I'm not so much a math geek, but I like to think I'm more of a creative individual than school allowed for.

The biggest struggle with teaching at home is that you simply can't teach everything. I couldn't teach math for example, and other people would have trouble covering literature, etc. There are apparently these whole networks of home schooling parents that trade services. One day parent A takes the kids for a morning of math, the next day parent B does a day of art, then literature, and then a field trip of some sort to a museum or such.

I guess I prefer a more liberal education... music, art, literature, to the math / science one that public and private schools claim to support.

Oct. 20th, 2001 01:23 pm (UTC)
Can't Teach Everything
Oh I know that =) And I'm not that confident in my own teaching skills ("those who can..." and all =D) I'm probably going to enroll my children in a Montessori school and then enroll them in:

Manditory - music lessons (theory and piano), a Math school, Chinese school.

Optional - ballet, soccer, summer camp, Buddhism for Children sessions or whatever else they have interest in.

We might put them in Kumon for a year, or just long enough to get the experience points but not too long that it damages their reasoning skills.
Oct. 20th, 2001 01:50 pm (UTC)
Re: Can't Teach Everything
I'll bite; what's a Montessori School and what's Kumon?
Oct. 20th, 2001 03:49 pm (UTC)
Re: Can't Teach Everything
Montessori Online. I've heard really good things about it, I'm still trying to understand what exactly it means though.

Kumon is a Math exercise program where you do batches of practice questions, then timed tests that consist of the same types of questions that vary with the skill level (like 2+3, 5+8, 9+2, etc.). You only pass the test if you get all the questions right. After you pass, you go on to the next level (12+4, 15+7). Each skill level gets harder and harder. It goes on with subtraction, multiplication, division, fractions, and on and on.

It builds experience with simple calculations. The more you do it, the more you recognize patterns to the numbers and remember the answers. That's why I say, I wouldn't have my kids doing this for too long and I'd want to balance this rote drill exercising with the reasoning and problem solving technique.

Husband Guy did Kumon for 3 years. It's made a difference in his calculation speed.
Oct. 20th, 2001 04:38 pm (UTC)
Re: Can't Teach Everything
Yeah - need to teach the kids how to be able to play blackjack without sitting there staring blankly at the numbers for a second. I'm no good at the pattern recognition for the most part, and I blame that for my inability to play cribbage.
( 9 comments — Leave a comment )


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