Janelle weighed an unknown substance. It has a mass of 20.609 grams. She exposed the substance to a flame and carefully weighed the substance again. The substance then had a mass of 17.39 grams. Write an equation to determine the amount of mass, x, the substance lost.

Which statement describes the term economics? a. it is the study of using limited resources to fulfill wants and needs. b. it is the study of how governments fulfill the wants and needs of nations. c. it is the study of how people spend their money to fulfill wants and needs.

What is the inverse of the function f(x)=4x+8

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?