What is the sixth term of this sequence a1=-12,an=an-1+5

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Ineed to know the answer to this algebra question.

Given the following linear function sketch the graph of the function and find the domain and range. ƒ(x) = -5x + 4