Math

1.x(x-3)=4 means that x=4 and x-3=4
Is that right?


2.Is the sum of squares prime???

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asked by Tommy
  1. 1. no it doesn't
    even though by coincidence x = 4 does work, your other solution of x = 7 does not.
    What you are assuming to be true only works if the Right Side is equal to zero.
    in this case you have to expand it, ..
    x^2 - 3x - 4 = 0
    (x-4)(x+1) = 0
    then x = 4 and x = -1

    2. true, because it has no factors other than 1 and itself

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    posted by Reiny
  2. .x(x-3)=4 means that x=4 and x-3=4
    Is that right?

    x^2-3x-4=0

    (x-4)(x+1)=0

    x1=4 and x2=-1

    so if you put x = 4 then x-3 can't be equell to 4

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    posted by bark
  3. the rule is this: A prime can be written as a sum of
    two squares. I hope that helps

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    posted by dan

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