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Math Help - Find Value of c

  1. #1
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    Find Value of c

    A certain function has the form f(x) = ax + b
    where a and b ≠ 0.

    If f(5) = 1, f(-3) = 25 and f(c) = 0, what is the value of c?
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  2. #2
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    Quote Originally Posted by sharkman View Post
    A certain function has the form f(x) = ax + b
    where a and b ≠ 0.

    If f(5) = 1, f(-3) = 25 and f(c) = 0, what is the value of c?
    f(5) = 5a + b = 1

    f(-3) = -3a + b = 25

    Solve for a and b simultaneously

    f(c) = ac + b = 0

    Sub in the now known values of a and b to find c.
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  3. #3
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    How...

    Quote Originally Posted by e^(i*pi) View Post
    f(5) = 5a + b = 1

    f(-3) = -3a + b = 25

    Solve for a and b simultaneously

    f(c) = ac + b = 0

    Sub in the now known values of a and b to find c.
    How did you determine that this is a system of two equations?
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  4. #4
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    Quote Originally Posted by sharkman View Post
    How did you determine that this is a system of two equations?
    Two values for f(x) were given and there are also two constants in f(x)
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