Question

John says the transformation rule (x, y) --> (x + 4, y + 7) can be used to describe the slide of the pre-image (4, 5) to the image (0, –2). What was his error?

Answer 1

The pre-image is the point you start with. To check the transformation rule, substitute the values of the coordinates (4, 5) into the rule. You get (4, 5) → (4+4, 5+7). Simplify to get (4, 5) → (8, 12). This is the image. Instead the rule was applied to the image. This is the source of the error.

Answer 2

For this case we have the following transformation:
(x, y) -> (x + 4, y + 7)
The ordered pair to which the transformation is applied is:
(x, y) = (4, 5)
Therefore, applying the transformation we have:
(4, 5) -> (4 + 4, 5 + 7) -----> (8, 12)
The error for this case is that John made the following transformation:
(4, 5) -> (4 - 4, 5 - 7) -----> (0, -2)
That is, rest the numbers instead of adding.
Answer:
his error was subtract instead of adding.
The correct answer is:
(8, 12)