3 and 9 are the first two terms in a geometric sequence. What is the arithmetic difference between the 7th term and the 5th term?
Pick
A) 3*3^2	B) 3* 3^13 - 5 * 3^11	C) 3^13	D) 8 * 3^6	E) 3^12 - 3^10
Common ratio = 9/3= 
<gadget id="calculator">9/3</gadget>
<output>3</output>
3   7th term= 3*3^7   5th term = 3*3^5   Difference = 3 * (3^7 - 3^5) = 3 * 3^5 *(3^2 - 1)   = 3 * 3^5 * 8   = 8 * 3^6....   8 * 3^6
<result>D</result>
3 and 9 are the first two terms in a geometric sequence. What is the arithmetic difference between the 7th term and the 5th term?