Answer :

The Priority is always to parenthesis. It means that in both equations, begin by operating what's inside the parenthesis. Then Subtract what's left.

For the first one you get:
[tex]72 - (63-8)[/tex]
[tex]72 - 55[/tex]
[tex]17[/tex]

For the second one you get:
[tex](72-63)-8[/tex]
[tex]9-8[/tex]
[tex]1[/tex]

Which mean that The 2 equations are not equal, because [tex]17 \ \textgreater \ 1[/tex]
Hope this Helps! :D
They are not equal because for each you get different answer.

[tex]72-(63-8) \\ 72-55 \\ 17[/tex]

[tex](72-63)-8 \\ 9-8 \\ 1[/tex]

17 and 1 are not equal.

Therefore, the two expressions  72-(63-8) and (72-63)-8 are not equal .