Given the system of linear equations. -x+y=3 and 2x+y=6 part a: use substitution to find the solution to the systems of equations. include all of your work in your final answer. part b: algebraically verify your answer to part a. include all of your work in your final answer.

Abby is collecting rainfall data. she finds that one value of the data set is a high-value outlier. which statement must be true? abby will use a different formula for calculating the standard deviation. the outlier will increase the standard deviation of the data set. the spread of the graph of the data will not change. abby will not use the mean when calculating the standard deviation.