An expression is equivalent to 54 if it represents the same numerical value as 54.
The following options are equivalent to 54:
53 + 1
54
54.5 - 0.5
54.57 - 0.07
54.512 - 0.512
The options that are not equivalent to 54 are:
(53)4
0511
516
054.512
Note that a number followed by a trailing zero is not equivalent to the same number without trailing zero as trailing zeroes don't change the value of the number.