Final answer:
The expression x^2-4x-xy+4y can be factored by grouping and then factoring out common terms to get the complete factored form as (x - y)(x - 4).
Step-by-step explanation:
To write the expression in complete factored form, we look for common factors and group terms to factor by grouping. Let's consider the given expression x^2-4x-xy+4y. We can rearrange and group the terms to begin factoring:
x^2 - xy - 4x + 4y
We can factor out an x from the first group and a 4 from the second group:
x(x - y) - 4(x - y)
Now we see that (x - y) is a common factor, so we factor it out:
(x - y)(x - 4)
This is our expression in complete factored form.