Question

Tamara says she used the GCF to factor the expression 21x + 56xy as 7(3x + 8xy). Is she correct? Explain.

Answer 1

Answer:

Tamara  incorrectly factored the whole expression.

Step-by-step explanation:

Note that

• 21x=3·7·x;
• 56xy=2·2·2·7·x·y.

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.