Answer:
See below for answers
Explanation:
To dialate means to change in size. K is the scale factor basically, and since K=7, we are going to multiply each of the coordinates by 7:
A(-3,1) -> A'(-21,7)
B(2,4) -> B'(14,28)
C(0,-4) -> C(0,-28)
See how we got those now?