## College Algebra (11th Edition)

4x$y^{3}$(x$y^{2}$ - 2)
The answer the student gave was not correct because he did not completely factor it out. The GCF is actually 4x$y^{3}$, so we factor out 2 again from his answer to get 4x$y^{3}$(x$y^{2}$ - 2).