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If \(a\) and \(b\) are positive numbers, \(2^a = b^3\) and \(b^a = 8\), find the value of \(a\) and \(b\)

  • A.a = 2, b = 3
  • B.a = 3, b = 2
  • C.a = b = 3
  • D.a = b = 2

Answer: B

Exp: \(2^a = b^3 ....(1)\)

\(b^a = 8 ....(2)\)

cubing both sides of equation \((2), (b^a)^3 = 8^3\)

\(\Rightarrow b^{3a} = (b^3)^a = 512\).

from \((1), (2^a)^a = (2^3)^3\).

comparing both sides, a = 3

substiting a in (1), b = 2

 

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