top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

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

+1 vote
1,224 views
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

Share this puzzle
Facebook Share Button Twitter Share Button LinkedIn Share Button

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



Similar Puzzles
+1 vote

If
x+y+z = 7
2x-y+z = 4
Then
11y-10x = ??

+1 vote

If
x, y, z are 3 non zero positive integers such that x+y+z = 8 and xy+yz+zx = 20,
then
What would be minimum possible value of x*y^2*z^2

+1 vote

If
abcde=1 (where a,b,c,d and e are all positive real numbers)
then
what is the minimum value of a+b+c+d+e?

...