Question

Your friend incorrectly factors the expression below as 7​x(3​-4xy). Factor the expression below correctly. What error did your friend​ make?

21x-28xy

Answer 1

To factor the expression 21x - 28xy correctly, we can first find the greatest common factor (GCF) of the two terms. The GCF of 21x and 28xy is 7x.

Next, we divide each term by the GCF and factor out the resulting expression.

21x - 28xy = 7x(3 - 4y)

So the correct factored expression is 7x(3 - 4y).

The error your friend made is mistakingly factoring out a 7 from both terms instead of factoring out the GCF, which is 7x.