After a dilation with a center of (0, 0), a point was mapped as (4, –6) → (12, y). A student determined y to be –2. Evaluate the student's answer.

Question

After a dilation with a center of (0, 0), a point was mapped as (4, –6) → (12, y). A student determined y to be –2. Evaluate the student's answer. A. The student is correct. B. The student incorrectly calculated the scale factor to be –2. C. The student incorrectly divided by the scale factor instead of multiplying by it. D. The student incorrectly added the scale factor instead of multiplying by it.

Answer 1

 

Solution :

 

B. The student incorrectly calculated the scale factor to be –2.

 

explanation

After a dilation with a center of (0, 0), a point was mapped as (4, –6) → (12, y)

                                                                                           (4*3, -6*3) -> (12,-18)

 

so scale factor is 3