✓ Correct answer: D. 6First convert 16<sup>n </sup>to the same base 4. You know 16 = 4 x 4 = 4<sup>2</sup> , so you can write 16<sup>n </sup>= (16)<sup>n </sup>= (4<sup>2</sup>)<sup>n</sup> = 4<sup>2n</sup>. We know that given 16<sup>n</sup> = 4<sup>12</sup>, so we can write 4<sup>2n</sup> = 4<sup>12</sup> Since both have ase 4, their powers are equal 2n = 12, or n = 6.<br/><br/><b>Key takeaway: </b>When solving problems involving exponents, base is to be seen carefully. It is easy to simplify, as long as they have the same base. Remember following simple formulae:a<sup>m</sup> x a<sup>n </sup>= a<sup>m+n</sup>, a<sup>m</sup> / a<sup>n</sup> = a <sup>m-n</sup> , (a<sup>m</sup> ) <sup>n</sup> = a <sup>m x n</sup> , (a<sup>m </sup>) <sup>1/n</sup> = a <sup>m/ n</sup>
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