FINITE GEOMETRIC SERIES (FORMULA)

What is the sum of the first ten terms of the sequence 4, -12, 36, -144 . . . ?

• 59,050
• -59,048
• -78,732
• 118,096

Find the 10th term of the following geometric sequence

5, 20, 80, 320, ...

BE CAREFUL - this question is asking for a term value NOT a sum

• 81,920

• 327,680

• 1,310,720

• 5,242,880

Answer explanation

a_n=a₁(r)^n-1

a_n=5(4)^n-1

a₁₀=5(4)^10-1

The sum of an finite Geometric series is given by:

• 
• 
• 
• 

What is the sum of the first 8 terms of the geometric sequence: 1 , 3 , 9 , 27 , . . . ?

• 3,260

• 3,270

• 3,280

• 3,290

Find S₈ for: -1 - 3 - 9 - 27...

• -3280

• -3135

• -3323

• -3343

Find the sum of the first 6 terms of the geometric sequence 2, 8,32,128,... .

• 3072

• 7320

• 2370

• 2730

Which formula would you use to find the sum of this series?

• 
• 
• 
• Expand and Add

Find the sum of the first 9 terms:  -2 + -6 + -18 + ...  

• -59,048
• -39,366
• -19,682
• -4,374

Determine the sum of the seri es written in Sigma Notation. 

• -65104
• -71570
• -73483
• -22003

• 11.74
• 13.32
• 29.97
• 39.96