math-Algebra

Hey i need help on this problem.
8-9t=21t-17
Can someone show me how to do it?

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  1. 8-9t=21t-17

    +9t

    8=30t-17

    25=30t

    5/6=t

    -30t=-25

    (i just cross examined)

    answer
    5/6=t

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  2. We have this equation:

    8 - 9t = 21t - 17

    We need to find t.

    This is called solving for t.

    We first combine like terms.

    -9t - 21t = -8 - 17

    Do you see what I did?

    I placed all numbers with the letter t on the left side of the equation and all the constants on the right side of the equation.

    It really does not matter where you place the numbers with or without variables.

    The important thing to remember is the fact that you MUST change the sign of each number or term when crossing over the equal sign. Do you see it above?

    We have this new equation:

    -9t - 21t = -8 - 17

    We now add and get:

    -30t = -25

    To find t, we now divide both sides of the equation by the coefficient, which in this question happens to be -30.

    t = -25/-30

    t = 25/30

    t = 5/6

    Done!

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  3. 8-9t=21t-17

    You first want to get the unknowns on one side of the equation and the knowns on the other.

    8 + 17 = 21t + 9t
    25 = 30t
    ? = t

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    Ms. Sue
  4. thank you

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  5. You're welcome.

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    Ms. Sue
  6. How bout you and me get together?

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  7. i don't get this
    8-9*.83333333333 does not equal 21*.83333333333-17

    WHen you substitute in 5/6 it doesn't equal PLEASE HELP TNX!!!!!!

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