The sequences are 7, 6, 5, 4,.........
Find the common difference by subtracting successive terms.
The distance between terms are constant.
The common difference is –1.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")