We are asked to find out whether the given expressions are equivalent or not
Part A:
These two expressions are equivalent since the sum of four individual x is equal to 4x.
For example:
Substitute x = 2
As you can see, the result of both expressions is equal therefore, these are equivalent expressions.
Part B:
These two expressions are not equivalent since, in the first expression, 5 is being multiplied with x and in the second expression 5 is being added to x.
For example:
Substitute x = 1
As you can see, the result of both expressions is not equal therefore, these are not equivalent.