Answer: The point (-10,-20) becomes (-8,-16) & point (15,25) becomes (12,20).
Step-by-step explanation:
When a point (x,y) is dilated by a scale factor k from the origin, then the new points become

The given rule of dilation : (x,y) →(0.8x, 0.8y)
The first point is (-10,-20), so its image will be

So, the point (-10,-20) becomes (-8,-16).
The second point is (15,25), so its image will be

So, the point (15,25) becomes (12,20).
Hence, the point (-10,-20) becomes (-8,-16) & point (15,25) becomes (12,20).