7.) 170
8.) 9
9.) 44
10.) -124
11.) -99
12.) 84
13.) 88
14.) -1080
15.) -27
16.) -81
17.) -27
18.) -81
First term: -9
Common difference: 7
a(n) = -9 + 7(n-1), for n = {1, 2, 3, ... }
Check: what is the first term? let n=1. Then a(1) = -9 + 7(1-1) = -9.
This is correct.
Answer:
5.5 years old.
Step-by-step explanation:
Let D represent present age of Robert's dog and C represent present age of Karen's cat.
We have been given that Robert's dog is 4 years older than Karen's cat. We can represent this information in an equation as:

We are also told that in 3 years, the sum of the ages of Robert's dog and Karen's cat will be 13. After 3 years age of dog and cat would be
and
respectively.
We can represent this information in an equation as:

From equation (1), we will get:

Upon substituting this value in equation (2), we will get:

Combine like terms:





Therefore, Robert's dog is 5.5 years old right now.
Yeah not just one letter but two letters perpendicular to another two letters. Each 2 letters like AB is a straight line which is crossed by another 2 letters making it perpendicular.