sat-dog

Choice D is correct. Two fractions can be added together when they have a 2 common denominator. Since k 0, multiplying the second term in the given 42 42 2 expression by k yields ^ akhk , which is equivalent to ak . Therefore, the 42 a k +42 k 42 a+42 ak 2 k expression ak can be written as which is equivalent to 42 +42 2 k k k a ak . Since each term in the numerator of this expression has a factor of 42 a, k the expression 42 a +42 ak 2 can be rewritten as 42 a^ 1 h +42 a^k 2 h , or 42 a^ 1+ k 2 h , k k k 42 2+1 which is equivalent to a^k h. k 42 a+42 a Choice A is incorrect. This expression is equivalent to . Choice B is k k incorrect and may result from conceptual or calculation errors. Choice C is 42 a+42 incorrect. This expression is equivalent to a. k