Awnser: (15,15)
The image of (3,3) after a dilation by a scale factor of 5 centered at it's origin would be (15,15), I believe. From what I remember, if it's asking for a dilation by a scale factor, you're basically just multiplying that point (the 3,3) by whatever the scale factor is (5 in this case). So for example, here you would just multiply the (3,3) by 5, since 5 is our scale factor. And you would get (15,15). I hope this helps, I'm quite new to this.