Answer:8/10
Step-by-step explanation:
<u>Given</u>:
The given expression to find the nth term of the sequence is 
The first term of the sequence is 
We need to determine the third term of the sequence.
<u>Second term:</u>
The second term of the sequence can be determined by substituting n = 2 in the nth term of the sequence.
Thus, we have;




Thus, the second term of the sequence is -40.
<u>Third term:</u>
The third term of the sequence can be determined by substituting n = 3 in the nth term of the sequence.
Thus, we have;



Thus, the third term of the sequence is 120.
Given:
The sequence is 25, 20, 15, 10, 5.
To find:
The ninth term of the given sequence.
Solution:
We have,
25, 20, 15, 10, 5
It is an AP because the difference between two consecutive terms are same.
Here,
First term (a) = 25
Common difference (d) = 20-25
= -5
The nth terms of an AP is

Where, a is the first term and d is the common difference.
Putting a=25, n=9 and d=-5 to get the 9th term.




Therefore, the ninth term of the given sequence is -15.
Answer:
Explanation: L = longer piece S = shorter piece
L + S = 22
L = 4 + S
S + S + 4 = 22
-4 -4
S + S = 18
S = 18/2 = 9 cm
L = 4 + S —> 4 + 9 = 13 cm
To confirm:
13 cm + 9 cm = 22 cm
Therefore, the shorter piece is 9 cm.