Which of the following is equal to 3^k*7^(k-1)?
Answers:	A) 3*21^(k-1)	B) 7*21^(k-1)	C) 21^k	D) 3*21^k )	E) 21^(2k-1)
3^k*7^(k-1) = 3*3^(k-1)*7^(k-1) = 3*21^(k-1)   The answer is 3*21^(k-1).
<result>A</result>
Which of the following is equal to 3^k*7^(k-1)?