Answer:
Tamara incorrectly factored the whole expression.
Step-by-step explanation:
Note that
Mark in bold all common factors, then GCF(21x,56xy)=7·x=7x.
Thus,
21x+56xy=7x(3+8y).
Hence, Tamara correctly found the GCF of numbers 21 and 56, but incorrectly factored the whole expression.