Can someone me with this question i just need to get the right answer

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?

What is the anwers for 9+2x=5x-3-x

What is the absolute value of the complex number -4-sqrt2i