Find all real numbers x and y that solve the system of equations log3x2+log2y3=1, log9x4+log4y9=2.
Solution
Denote a=log3x2 and b=log2y3. Then log9x4=log39log3x4=22log3x2=aandlog4y9=log24log2y9=23log2y3=23b. Inserting this into the initial equations we get a+b=1 and a+23b=2. Subtracting the first equation from the second yields 21b=1 or b=2. From the first equation we get a=−1. From log3x2=−1 it follows that x2=31 or x=±31, and from log2y3=2 we have y3=4 or y=34.
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Source: MathNet,
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