Answer:
[tex] 1.({(21)}^{ \frac{1}{2} } {) }^{ \frac{1}{2} } \\ 2.{(a + b)}^{ \frac{1}{4} } \\ 3. {(y)}^{ \frac{3}{4} } \\ 4. {(2x)}^{ \frac{ \frac{5}{3} }{?} } [/tex]
hope can help
