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Homework Help: Algebra 2 Problems

  1. May 20, 2004 #1
    Problem 3. The sum of the two numbers is 3 and the sum of their reciprocas is 12/5. Find the numbers.


    Problem 7. What is the linear term of the equation
    q = 3x^2 + 2x - 1?

    Problem 9. Write the equation of the ellipse with foci at (12,1) and (-12,1) and the endpoints of the major axis at (0,6) and (0,-4) Then graph the ellipse.


    Problem 19. If f(x)=3x^2-2 and g(x)=2x^2+3, find[f o g](-4)
     
  2. jcsd
  3. May 20, 2004 #2

    arildno

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    Problem 35. What have you done so far?
     
  4. May 20, 2004 #3
    Problem 3.

    Let your two unknown numbers be m and n. You're given two statements about the relationship between m and n. Each statement can be written as an equation. You'll have two equations and two unknowns. You can solve this system of equations simultaneously for m and n.

    The first equation is absolutely trivial. Hint on the second: The reciprocal of m is 1/m .

    Show us a little of what you've done so we can help a little more.
     
  5. May 22, 2004 #4

    ShawnD

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    2 equations, 2 variables, 2 easy :biggrin:

    [tex]x + y = 3[/tex]

    Isolate one of the variables.

    [tex]x = 3 - y[/tex]

    Now write the other equation

    [tex]\frac{1}{x} + \frac{1}{y} = \frac{12}{5}[/tex]

    Substitute the isolated variable.

    [tex]\frac{1}{3 - y} + \frac{1}{y} = \frac{12}{5}[/tex]

    Now multiply each term by all of the denominators.

    [tex]5y + (15 - 5y) = 36y - 12y^2[/tex]

    Just solve for that equation and you'll have Y. Then substitute that answer for Y back into the first equation.


    I think you are supposed to fill in -4 for the g equation, then use the g equation as x in the f equation. It's like this:
    f(g(-4)) = ??
     
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