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Math Help - problem with numbers

  1. #1
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    problem with numbers

    For which numbers N, is N*-2 greater than -2? In other words, for which numbers N, is N*-2>-2?
    Investigate theis question as follow:

    A) Without using a calculator, multiply -2 by the given numbers. Show your work. In each case, determine wheather the resulting product is greater than -2 or not.

    3.15, ,1.01, 0.85, 0.002, -0.3, -4.2
    4 3/5, 1 2/3, 9/10, 3/5, -7/8, -1 1/8

    B) Based on your answers in part a and on th emeaning and rules of multiplication, describe the collection of all numbers N, for which N8-2 is greater than -2.

    Thank you
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  2. #2
    A riddle wrapped in an enigma
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    Well, nobody seems to want to respond to this one, so here goes.

    In order for N\cdot-2>-2,

    N<1

    For instance; if N=\frac{1}{2}, then \frac{1}{2}\cdot-2=-1 which is greater than -2.

    If N=-2, then -2\cdot-2=2, which is greater than -2.

    So, there you go.

    I assume you can multiply -2 times all your sample numbers and compare the products to see if any are greater than -2.

    You'll find that 0.85, 0.002, -0.3, -4.2, \frac{9}{10} , \frac{3}{5} , \frac{-7}{8} and -1\frac{1}{8} \, all conform to the fact that N < 1 is the set of numbers that satisfy your original statement.
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  3. #3
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    Thank you so much!
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