## Algebra: A Combined Approach (4th Edition)

$a.$ $y^{4}$ $b.$ $x$
a. Since they are all the same variable, it would be the smallest exponent to which y is raised, or 4; hence, $y^{4}$. b. The GCF is $x^{1}$ or $x$, since $1$ is the smallest exponent raise to $x$.