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-   -   The sum of the digits of a two-digit number is 9. The tens digit is 3 less than the (https://www.askmehelpdesk.com/showthread.php?t=505784)

  • Sep 8, 2010, 03:27 AM
    joven
    The sum of the digits of a two-digit number is 9. the tens digit is 3 less than the
    Square of the units digit. Find the number.
  • Sep 8, 2010, 08:59 AM
    ebaines
    You ned to set this problemn up as two equations in two unknowns. Let's call the tens digit 'A', and the units digit 'B'. You know that:

    A + B = 9 (since the sum of the tens digit and units digit is 9)
    A = B^2-3 (since the tenbs digit is 3 less than the square of the units digit)

    Yo can now rearrange the first equation to get A by utself, then substitute that equation for A into the second equation. At this point you'll have one equation for B, which will be a quadratic that you can factor to determine B. Then finally substitute that value for B back into the first equation to figure out what A is. Good luck, and post back with what you get for a final answer.



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