Answer:

Step-by-step explanation:
I am assuming that you mean (4,−9) and (8, -3).

Hope this helps.
1.No error , he divided by 16 in the 2 sides .
2.no error ,he made sure that 16/16 is one while d/16 remains
3.no error , he square rooted both sides
4.error, as the root gives one positive value and one negative value not only a positive value ,the answer should have been t=+-(d/4)
5.error,he disturbed the whole equation by rooting d only he should have rooted both sides

Step-by-step explanation:



