Yes, Heather is correct. The expressions are not equivalent
Solution:
Given that,
Heather says, the following expressions are not equivalent

Because one expression has a term that is subtracted and the other does not
Combine the like terms in first expression:

Let us first expand the second expression
By distributive property
a(b + c) = ab + bc
Therefore,

Thus the two expressions are:

Yes both the expressions are not equivalent
Because, in first expression 2x is added to 8
But in second expression, 8 is subtracted from 2x
Thus heather is correct