Question

find the scale factor.

Explanation:

Step1: Identify side lengths

First, find the length of a horizontal side of the original rectangle ABCD. From the grid, the horizontal distance from A(2,18) to B(12,18) is $12-2=10$.
Next, find the length of the corresponding horizontal side of the dilated rectangle A'B'C'D'. From the grid, the horizontal distance from A'(-10,-4) to B'(-5,-4) is $-5-(-10)=5$.

Step2: Calculate scale factor

The scale factor is the ratio of the dilated side length to the original side length.
$\text{Scale Factor} = \frac{\text{Length of } A'B'}{\text{Length of } AB} = \frac{5}{10} = \frac{1}{2}$

Answer:

$\frac{1}{2}$