Perform the indicated operation
1.
[tex] \sqrt{16} - \sqrt{9} [/tex]
2.
[tex]2 \sqrt{3} + 4 \sqrt{27} [/tex]
3.
[tex]3 \sqrt{2} \times 7 \sqrt{3} [/tex]
4.
[tex] \frac{ \sqrt{5} }{2} [/tex]
5.
[tex] \frac{7}{ \sqrt{5} } [/tex]
​