Calculate the value of the equation wihtout the use of a calculator. you may use:
reduction
co-functions
double angles
special angles
etc.

show all steps clearly.

Solve the system by the elimination method. x + y - 6 = 0 x - y - 8 = 0 when you eliminate y , what is the resulting equation? 2x = -14 2x = 14 -2x = 14

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?

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.