( 567z^9y^11)^(1/4)
(81 * 7)^(1/4) * (z^9)^(1/4) * (y^11)^(1/4)
(81)^(1/4) * 7^(1/4) * z^(8/4 + 1/4) * y^(8/4 + 3/4)
(3^4)^(1/4) * 7^(1/4) * z^(2 + 1/4) * y^(2 + 3/4)
3^1 * 7^(1/4) * z^2 * z^(1/4) * y^2 * y^(3/4)
3z^2y^2 ( 7^(1/4) * z^(1/4) * y^(3/4) )
3z^2y^2 ( 7 * z * y^3)^(1/4)
3z^2y^2 4 √ [ 7 z y^3]