`a)`
`3 \sqrt{3} + 64`
` = (\sqrt{3})^2 . \sqrt{3} + 64`
` = (\sqrt{3})^3 + 4^3`
` = (\sqrt{3} + 4)[ (\sqrt{3})^2 - \sqrt{3} . 4 + 4^2]`
` = (\sqrt{3} + 4)(3 - 4 \sqrt{3} + 16)`
`b)`
`a + \sqrt{a} (a \ge 0)`
` = (\sqrt{a})^2 + \sqrt{a}`
` =\sqrt{a} (\sqrt{a} + 1)`
