Solving Exponential Equations with Compatible Bases
8.4: Solving Exponential Equations with Compatible Bases. Original editorial SAT preparation with three worked examples, ten flashcards, and thirty practice questions. Educator-review draft.
Equal-base equations
Objective: Solve by equating exponents for an injective exponential base.
Prerequisite skills: exponent laws and solving linear equations. For b>0 and b≠1, the function b^x takes each positive output only once. Therefore b^u=b^v implies u=v. This avoids logarithms when both sides have compatible bases. Common error: equating exponents while the bases still differ. Restrictions and interpretation: Match powers only after obtaining equal positive bases other than 1.
Formulas
Worked examples
Try itSolve 3^(2x + 1) = 3^47.Show answer
The positive base 3 is not 1, so equate exponents: 2x+1=47. Subtract 1 and divide by 2: x=23. Therefore the requested answer is 23.
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