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If 6xy + 10x +15y = 39 then find the minimum value of 2x+3y (x, y are positive and real)?

+1 vote
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If 6xy + 10x +15y = 39 then find the minimum value of 2x+3y (x, y are positive and real)?
posted May 12, 2015 by Ankit Kamboj

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1 Answer

+3 votes

2x + 3y = (39 - 6xy)/5

Now by first making 39 - 6xy a multiple of 5 , we get if 39-6xy=30 , or 6xy=9 we get xy=3/2 or 2x+ 3y=6 (x=3/2 , y=1) and rest all cases we are getting either x,y imaginary or 2x+ 3y >6

so minimun value is 6

answer May 13, 2015 by Ankit Kamboj



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