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advanced-math

If 2x=3y2^x = 3^y and x=6x = 6, what is yy?

A

y=6ln(2)ln(3)y = \frac{6\ln(2)}{\ln(3)}

B

y=6y = 6

C

y=6ln(3)ln(2)y = \frac{6\ln(3)}{\ln(2)}

D

y=4y = 4

Correct Answer: A

Choice A is the correct answer. Use logarithms to solve for yy.

  1. Given: 26=3y2^6 = 3^y, so 64=3y64 = 3^y.
  2. Take natural log: ln(64)=ln(3y)=yln(3)\ln(64) = \ln(3^y) = y\ln(3).
  3. Solve: y=ln(64)ln(3)=ln(26)ln(3)=6ln(2)ln(3)y = \frac{\ln(64)}{\ln(3)} = \frac{\ln(2^6)}{\ln(3)} = \frac{6\ln(2)}{\ln(3)}.
  4. Numerical: y6(0.693)1.0993.79y \approx \frac{6(0.693)}{1.099} \approx 3.79.

💡 Strategic Tip: To solve ax=ba^x = b, use x=ln(b)ln(a)x = \frac{\ln(b)}{\ln(a)}.

Choice B is incorrect because36=729eq643^6 = 729 eq 64. Choice C is incorrect because this inverts the logarithms. Choice D is incorrect because34=81eq643^4 = 81 eq 64.