Here is an equation that will always equal 10 when x is a number from 2-9
but why?
( [ (2x + 4)x ] - x) 5
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x
Maybe I am writing the equation wrong, but this is how it should go.
X times 2 plus 4
multiply that by X
divide that by 2X
substract X from the answer found above
multiply that by 5
should get 10
dividing by 2x is included in the brackets. Maybe thats why you are confused.
this is your expression ...
$\displaystyle \left[\frac{(2x+4)x}{2x} - x\right]5$
note that in the fraction part, the x's cancel, leaving
$\displaystyle \left[\frac{2x+4}{2} - x\right]5$
now divide 2x+4 by the 2 ...
$\displaystyle \left[(x+2) - x\right]5$
the x's in the [brackets] cancel ...
$\displaystyle [2]5 = 10$