the difference between 7 times a number and 9 less than a number

Discussion in 'Calculator Requests' started by math_celebrity, Jul 8, 2019.

  1. math_celebrity

    math_celebrity Administrator Staff Member

    the difference between 7 times a number and 9 less than a number

    The phrase a number means an arbitrary variable, let's call it x.

    7 times a number means we multiply x by 7
    7x

    9 less than a number means we subtract 9 from x
    x - 9

    The difference between the two expressions means we subtract (x - 9) from 7x
    7x - (x - 9)

    Simplifying this, we have:
    7x - x + 9

    Grouping like terms, we get:
    6x + 9
     

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