166k views
18 votes
Use explicit formula to find the 10th of each geometric sequence

1. 1,9,81,729....
2. 2,8,32,128....
3. -9,27,-81,243...
4 .6,-24,96,384 ...
choose 2 question and solve them
thank you

User Iomv
by
3.4k points

1 Answer

6 votes

Answer:

1. 1*9^(10-1) = 387,420,489

2.2*4^(10-1) = 524,288

Explanation:

The explicit formula for a geometric sequence is a1 * r^n-1

Where a1 is your first term, r is your ratio, and n is the amount of terms you want in the sequence

To solve for the 10th number in the sequence, we simply plug 10 in for n.

Hope this helps

User Banjer
by
4.3k points