Which triangles are congruent in the diagram?

Which is an equation for the nth terms of the sequence 12,15,18,21

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.

How do you create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1?