ANSWER
B' has coordinates (16,14).
Step-by-step explanation
The given coordinates of square ABCD are :
A (2,7) , C (8,1),D (2,1)
In order to form a square, the coordinates of B should be: (8,7)
The mapping for dilation with a scale factor 2, about the origin is
![(x,y)\to (2x,2y)](https://img.qammunity.org/2020/formulas/mathematics/high-school/kgjwxe6czwkwh85yolv8posfxulvfqafxf.png)
This implies that:
![B(8,7)\to B'(2 * 8,2 * 7)](https://img.qammunity.org/2020/formulas/mathematics/high-school/vii9yyvnhipud2cj37q98klcwffeelug5h.png)
When we simplify we get:
![B(8,7)\to B'(16,14)](https://img.qammunity.org/2020/formulas/mathematics/high-school/sk6prlu9d707y9cnad3plf9num6ew215qt.png)
Hence B' has coordinates (16,14).