Solve
for .
State the domain before solving. A logarithm needs a strictly positive argument, so
Any candidate answer must clear this bar; writing the restriction down first is what makes the final check meaningful rather than an afterthought.
Isolate the logarithm. Divide both sides by the coefficient :
Leaving the right side as the exact fraction keeps the answer exact.
Convert to exponential form. The defining equivalence for logarithms is
Here , , , so
Solve for x. Add :
This is the exact answer; no further simplification is possible because is not an integer and and share no factor with .
Evaluate numerically and confirm the domain. Since ,
As a size check, and should be a little larger — it is ✓. And , so the logarithm is defined and the solution is valid.
Verify by substituting back. With : , and , so ✓.
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