Question 209204
( 1/x -1/a) / (x-a),,,,,,,LCD = ax
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(a-x)/(ax) * 1/(x-a),,,,invert  and  multiply
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(a-x) / (ax) * 1/-1(a-x),,,,,,simplify  by  canceling  like  terms
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-1/ax,,,,answer
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check,,,let  a=2..x=3,,,,both  original  and  answer  = -1/6,,,ok