Question 268584
9/10 -1/4- 1/2= ? 
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Find a common denominator and change all the fractions to that DEN.
It doesn't matter if it's the LCD or not.  On a test, don't waste time finding the LCD, just multiply them all together.
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10*4*2 = 80
--> 72/80 - 20/80 - 40/80
= 12/80
= 3/20
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