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

$2|2y+z|$
$\sqrt [4] {16(2y+z)^{4}}$=$\sqrt [4] {2^{4}\times(2y+z)^{4}}$ According to the text, if n is an even positive integer, then $\sqrt[n] {x^{n}}=|x|$. Therefore, $\sqrt [4] {2^{4}\times(2y+z)^{4}}=2|2y+z|$.