Problem:

 

Grant and Denise describe the sequence below in different ways. 

 

                        -4, 3, 10, 17, 24 …

     

Grant’s equation

 

 

Denise’s equation

 

 

 

 

y = 7x – 4

 

 

next = now + 7 with the first now being –4

 

Determine that both equations are correct and explain why one student is multiplying by 7 and the other is adding 7.