1+1 = ? 45 POINT QUESTION

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Now, martin can reasonably guess that the standard deviation for the entire population of people at the mall during the time of the survey is $1.50. what is the 95% confidence interval about the sample mean? interpret what this means in the context of the situation where 95 people were surveyed and the sample mean is $8. use the information in this resource to construct the confidence interval.

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !