[tex]\sqrt{16}[/tex]
16 can be factorized as
[tex]\begin{gathered} 16=4\cdot4 \\ so \\ 16=4^2 \end{gathered}[/tex]
Also,
-4*-4=16
so
[tex]\begin{gathered} \sqrt{16}=4 \\ \text{and} \\ \sqrt{16}\text{ = -4} \\ \sqrt{16}=\pm4 \end{gathered}[/tex]
I hope it helps you
