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very tough combination VIC og 122

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very tough combination VIC og 122

by resilient » Thu Feb 07, 2008 9:59 pm
an operation # is defined by the equation a#b = a-b/a+b, for all numbers a dn b such that a not equa -b. If a not equal -c and a#c=0, then c=

a. -a
b.-1/a
c. 0
d. 1/a
e. a
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by Saffa » Fri Feb 08, 2008 3:13 am
for a#c to be equal to zero and a <> -c, the numerator of the equation needs to be equal to zero.

i.e. because a#c = (a-c)/(a+c) and a+c is not equal to (<>) 0

The the following ust be true

a - c = 0
ie. a = c
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by blue_lotus » Fri Feb 08, 2008 5:30 am
If the fraction has to become 0 the numerator must be 0
in this case the numerator is a-c =0
which means a=c , hence the answer


Other information like a not equal to -c , is given to ensure the denominator is not zero. If denominator is zero the fraction becomes undefined.
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