What is the common difference in the arithmetic sequence 10, 8, 6, 4, ...?

The variable in a relation who’s value depends on the value of the independent variable is called what?

Need on this one asap im almost done with this subject

Lena reflected this figure across the x-axis. she writes the vertices of the image as a'(−2, 8), b'(−5, 6), c'(−8, 8), d'(−4, 2).