Find the all arranged triplets ,from positive real numbers ( a,b,c)

that: (a)bc=3,a(b)c=4,ab(c)=5,which (x) is the greatest integer less than or equal to x

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- Jun 21st 2012, 01:56 PMMhmh96Finding the triplets
Find the all arranged triplets ,from positive real numbers ( a,b,c)

that: (a)bc=3,a(b)c=4,ab(c)=5,which (x) is the greatest integer less than or equal to x - Jun 21st 2012, 04:39 PMrichard1234Re: Finding the triplets
Label the original equations (1), (2), and (3) in that order.

First, note that (otherwise , etc., contradiction).

Multiplying all three equations, we get .

We can prove that . Assume that . In order to satisfy (1), b must equal 3, otherwise c would have to be less than 1. If b = 3, . Solving for a via (2) and (3), we obtain and , no solution. Similarly, if , we get the same contradiction. If , , no solutions.

Therefore, . It follows that . I'll let you do the casework (I obtained at least two solutions btw).

(There should be {} with 1,2 and 1,2,4, but LaTeX interprets the brackets differently, and idk how to input them otherwise). - Jun 21st 2012, 04:52 PMReckonerRe: Finding the triplets
- Jun 22nd 2012, 12:22 AMrichard1234Re: Finding the triplets