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Forming a formula from a-b=c-d

  1. Mar 26, 2014 #1
    Hi, I am beginner in mathematics , I have the following relationship:


    I need to calculate c under the assumption that a, b and d are known values.
    I got c=a-b+d
    and c=a/b*d

    can I use any other formulas?!!
  2. jcsd
  3. Mar 26, 2014 #2


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    Gold Member

    c=a-b+d follows directly from the stated relationship. Where did you get c=a/b*d ???
  4. Mar 26, 2014 #3


    Staff: Mentor

    What you got above is correct. To solve for c, add d to both sides of the equation.

    I don't know how you got the equation below, but it's incorrect.
    The equation you started with is very simple, so the only possible differences are how the three terms on the other side are arranged, with a total of six ways.

    c = a - b + d
    c = a + d - b
    c = d + a - b
    c = d - b + a
    c = -b + a + d
    c = -b + d + a
  5. Mar 26, 2014 #4
    c=a-b+d follows from a-b=c-d

    c=a/b*d follows from a/b=c/d

    Did you write it down in a way that your -'s look like /'s ?
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