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A parallelogram has an area of 8x^2 - 2x -45. The height of the parallelogram is 4x + 9. I know the formula for a parallelogram is A=bh. Please work and explain how I get the length of the base of the parallelogram. Thanks

  • math -

    since a = bh and they give you a polynomial for a and h, you have to expect that b = a/h and (4x+9) divides (8x^2 - 2x -45)

    In fact, 8x^2 - 2x -45 = (4x+9)(2x-5)

    so, b = 2x-5

    If they had given you numbers, you'd have had no trouble doing the division. Don't be confused by their efforts to cloak the underlying simplicity of the question.

  • math -

    Factor(unfoil) the area to get:
    (2x-5)* (4x+9). When you divide that by the height, the result is the length of the base: (2x-5)
    Not sure if you're solving for x, but I don't think that there's enough information. Let me know if this helps you!

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