This is a lesson/slideshow presentation I made for my 8th grade PreAlgebra students.

1. Algebraic Sequences Obj. Generate an algebraic expression given part of a sequence.

3. EXAMPLE 1 Write an expression for the n th term in the sequence 3, 4, 5, 6, 7, …? Step 1 :  Construct a process chart showing the position and the corresponding term. 3 4 5 6 7 +1 +1 +1 +1 Position “ 0” 1 2 3 4 5 n Term

4. Determine the common difference (the change) of the terms. STEP 2 Common Difference: 1 This is the coefficient of n . 1 n

5. Reverse the pattern to find the “zero” term. STEP 3 3 4 2 5 6 7 -1 Zero term: 2 Position “ 0” 1 2 3 4 5 n Term

6. Common Difference: 1 FINISHING IT OFF Zero Term: 2 1 2 n + 2 n +

7. EXAMPLE 1 Write an expression for the n th term in the sequence 12, 8, 4, 0, -4, …? Step 1 :  Construct a process chart showing the position and the corresponding term. 12 8 4 0 -4 -4 -4 -4 -4 Position “ 0” 1 2 3 4 5 n Term

8. Determine the common difference (the change) of the terms. STEP 2 Common Difference: -4 This is the coefficient of n . -4 n

9. Reverse the pattern to find the “zero” term. STEP 3 12 8 16 4 0 -4 +4 Zero term: 16 Position “ 0” 1 2 3 4 5 n Term

10. Common Difference: -4 FINISHING IT OFF Zero Term: 16 -4 16 -4 n + 16 n +