iygoiviookkoo

bài 2:
$\displaystyle  \begin{array}{{>{\displaystyle}l}}
a,\ \sqrt{1} =\pm 1\\
b,\ \sqrt{9} =\pm 3\\
c,\ \sqrt{\frac{16}{9}} =\pm \frac{4}{3}
\end{array}$
bài 1:
căn bậc hai số học: 
$\displaystyle  \begin{array}{{>{\displaystyle}l}}
\sqrt{25} =5\\
\sqrt{0,64} =0,8\\
\sqrt{0,01} =0,1\\
\sqrt{\frac{9}{16}} =\frac{3}{4}
\end{array}$
căn bậc hai:
$\displaystyle  \begin{array}{{>{\displaystyle}l}}
\sqrt{25} =\pm 5\\
\sqrt{0,64} =\pm 0,8\\
\sqrt{0,01} =\pm 0,1\\
\sqrt{\frac{9}{16}} =\pm \frac{3}{4}
\end{array}$