Explain how to determine the successive terms for each of the following sequences. Then write an equation for the $n^{\text{th}}$ term of each sequence in the form $t(n) =$. 

1. $−3, 1, 5, 9, …$ 

   Hint (a):

   What is the difference between each successive term?

2. $40, 20, 10, 5, …$ 

   Hint (b):

   Try division.

3. $\frac { 3 } { 2 } , \frac { 5 } { 2 } , \frac { 7 } { 2 } , \frac { 9 } { 2 } , ...$ 

   Partial Answer (c):

   Add $\frac{2}{2}$ to each successive term.