Answer:
Alexander is incorrect because the expressions are not equivalent.
Explanation:
If the expression is evaluated for any value of x, y; the result will not be same.
For instance, let assume x = 1 and y = 2
3x + 4y = 3 + 4 = 7
(3)(4) + xy = (3)(4) + (1 * 2) = 12 + 2 = 14
So, the expressions are not the same and Alexander is incorrect.