What does it mean to say that a data point has a residual of 0

Asequence is defined recursively using the formula f(n + 1) =f(n) - 5. which sequence could be

Ineed the solution to this problem and the steps.

The image of abc is a'b'c. what transformations would result in this image? abc is reflected over the line x = 1, then is rotated -90° around the origin. abc is reflected over the line y = x - 1, then t: (x, y) → (x - 1, y - 1). abc is rotated 90° around the origin, then is reflected over the y-axis. abc is rotated -90° around the origin, then is reflected over the line y = -1.