Answer:
Coordinates of B' → (7.5, 35.5)
Explanation:
Rule for the dilation of a point with a scale factor 'k' about the origin,
(x, y) → (kx, ky)
By this rule coordinates of the image point B' when scaled by a scale factor of 2.5,
B(3, 15) → B'(2.5 × 3, 2.5 × 15)
→ B'(7.5, 37.5)
Therefore, coordinates of point B' → (7.5, 35.5)