<PRE><B>Question 141658</B>
( 1/a squared b c ) - (2a/b squared c) - 3/a c 
[1/a^2bc] - [2a/b^2c] - [3/ac]
You need a least common denominator for each fraction:
lcm = a^2b^2c
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ab^2c/lcm - 2a^3/lcm - 3ab^2/lcm

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[ab^2c -2a^3 - 3ab^2]/lcm

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Cheers,
Stan H.</PRE>