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Math Help - Long-ish Equation: Need Help!

  1. #1
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    Talking Long-ish Equation: Need Help!

    Like the last problem I had with 0 of 0, I think this one has an easy fix. But there's not example in the textbook and it's Saturday, so obviously there's no teacher to turn to.

    I'm close, but here it is:

    2[4 -2(3-x)]-1= 4[2(4x-3) +7]-25

    Here's what I did:

    1st Step: 2[4 -6 +2x]-1 = 4[8x-6+7]-25

    2nd: 2[-2 +2x]-1 = 4[8x +1]-25

    3rd: -4 +4x -1 = 32x +4 -25

    4th: -5 +4x = 32x -21

    5th: ...

    Oh. I just figured it out.

    I subtract 4 from 4 and then 4 from 32x to get 28, which I then divide by itself.

    Then I add 21 to -21 and add the same to the -5 to get 16...

    So 16 over 28 reduces to 4 over 7. X= 4 over 7

    So I guess now my question is this: why is this equation different in that I want X on the right side? Obviously there's a rule on this but what specifically is it? Is it that you always subtract the smaller number from the bigger number? Is that it?
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  2. #2
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    Quote Originally Posted by Ingersoll View Post
    Like the last problem I had with 0 of 0, I think this one has an easy fix. But there's not example in the textbook and it's Saturday, so obviously there's no teacher to turn to.

    I'm close, but here it is:

    2[4 -2(3-x)]-1= 4[2(4x-3) +7]-25

    Here's what I did:

    1st Step: 2[4 -6 +2x]-1 = 4[8x-6+7]-25

    2nd: 2[-2 +2x]-1 = 4[8x +1]-25

    3rd: -4 +4x -1 = 32x +4 -25

    4th: -5 +4x = 32x -21

    5th: ...

    Oh. I just figured it out.

    I subtract 4 from 4 and then 4 from 32x to get 28, which I then divide by itself.

    Then I add 21 to -21 and add the same to the -5 to get 16...

    So 16 over 28 reduces to 4 over 7. X= 4 over 7

    So I guess now my question is this: why is this equation different in that I want X on the right side? Obviously there's a rule on this but what specifically is it? Is it that you always subtract the smaller number from the bigger number? Is that it?
    Dear Ingersoll,

    You can do it either way you want.

    -5+4x=32x-21

    Substract 32x from both sides,

    -5+4x-32x=32x-21-32x

    -5+(-28x)=-21

    -5-28x=-21

    Add 5 both sides,

    -5-28x+5=-21+5

    -28x=-16

    x=\frac{-16}{-28}=\frac{16}{28}=\frac{4}{7}

    Hope this will help you.
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  3. #3
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    Quote Originally Posted by Ingersoll View Post
    2[4 -2(3-x)]-1= 4[2(4x-3) +7]-25
    Simplify as much as possible before "getting going!":
    Move the -25:
    2[4 - 2(3 - x)] + 24 = 4[2(4x - 3) + 7]
    Divide by 2:
    4 - 2(3 - x)] + 12 = 2[2(4x - 3) + 7]
    carry on...
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  4. #4
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    Quote Originally Posted by Ingersoll View Post
    4th: -5 +4x = 32x -21
    So I guess now my question is this: why is this equation different in that I want X on the right side? Obviously there's a rule on this but what specifically is it? Is it that you always subtract the smaller number from the bigger number? Is that it?
    Nooooooo.......just rewrite like this:
    32x -21 = -5 + 4x
    Kapish?
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  5. #5
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    Cool. Thank both of you very much.
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