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Math Help - Guyz i need help T_T... urgenttt T_T

  1. #1
    Senior Member
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    Guyz i need help T_T... urgenttt T_T

    1.) Lita is fifteen yrs older than her sister Tess. Six years ago, Lita was 6 times as old as Tess. Find Their present ages...

    2.) Fred is 3 times as old as his sister Mary. Four years ago, he was five times as old as his sister. Determine their present ages...
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  2. #2
    Member Glaysher's Avatar
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    Solve

    1. x - 6 = 6(x - 6 - 15) for Lita's present age

    2. 5(x - 4) = 3x - 4 for Mary's present age
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  3. #3
    Super Member

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    Hello, EA!

    I assume your difficulty is the set-up.
    Try setting up the facts in a table . . .


    1.) Lita is fifteen yrs older than her sister Tess.
    Six years ago, Lita was 6 times as old as Tess.
    Find Their present ages.

    Make a row for each person in the problem: Lita and Tess.
    Code:
            |
    - - - - + - - - - - - - - -
       Lita |
    - - - - + - - - - - - - - -
       Tess |
    - - - - + - - - - - - - - -

    Make a column for each time period in the problem:
    . . Now and sometime in the Past.
    Code:
            |   Now   |  Past |
    - - - - + - - - - + - - - +
       Lita |         |       |
    - - - - + - - - - + - - - +
       Tess |         |       |
    - - - - + - - - - + - - - +

    "Lita is 15 years older than Tess."
    . . Let x = Tess' age (now).
    . . Then x+15 = Lita's age (now).
    Write those in the "Now" column.
    Code:
            |   Now   |  Past |
    - - - - + - - - - + - - - +
       Lita |  x + 15 |       |
    - - - - + - - - - + - - - +
       Tess |    x    |       |
    - - - - + - - - - + - - - +

    Six years ago, they were both six years younger.
    . . Lita was x + 9 and Tess was x - 6.
    Write those in the "Past" column.
    Code:
            |   Now   |  Past |
    - - - - + - - - - + - - - +
       Lita |  x + 15 | x + 9 |
    - - - - + - - - - + - - - +
       Tess |    x    | x - 6 |
    - - - - + - - - - + - - - +

    The equation always comes from the last column.

    We are told: Six years ago, Lita was six times Tess.
    . . . . . . . . . . . . . . . . . . . . \downarrow\quad\;\;\downarrow\quad\;\downarrow \quad\;\,\downarrow\qquad\;\;\downarrow<br />
    and there is our equation: . x + 9 \:= \:\;\;6\quad\times\quad(x - 6)


    Now try it on the second problem . . .

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  4. #4
    Senior Member
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    Edit
    Thanks a lot sir !!
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