Question

Producing a Pre-image from Given Information
On a coordinate plane, an image rectangle has points (negative 5, 0), (5, 0), A prime (5, negative 5), (negative 5, negative 5).

An image of a dilation about the origin is shown.

Which represents the pre-image of A'?
(5, –5)
(0, 0)
(3, –3)
(Five-thirds, negative five-thirds)

Answer 1

Answer: (3, −3)

Reason: The dilation about the origin has scale factor 5/3 (3 dilated by 5/3 gives 5). So divide A' coordinates (5, −5) by 5/3 (i.e. multiply by 3/5) to get (3, −3).