Question

mik dg cần gấp ạ, mik k bt sao nó cứ hay bị lỗi í

Answer 1

1. a. \(\sqrt{25}=\pm5\)

b. \(\sqrt{0,0001}=\pm0,01\)

c. \(\sqrt{\dfrac{9}{25}}=\pm\dfrac{3}{5}\)

d. \(\sqrt{-6}=\varnothing\)

2. a. \(\sqrt{25-9}=\sqrt{16}=\pm4\)

b. \(\sqrt{0,01}-\sqrt{0,25}=\pm0,1-\pm0,5=\left[{}\begin{matrix}-0,4\\0,4\\0,6\\-0,6\end{matrix}\right.\)

c tương tự nhé

Answer 2

Bài 3:

a) \(\sqrt{6}< \sqrt{16}=4\)

b) \(\sqrt{11.3}=\sqrt{33}< \sqrt{44}\)

Bài 4:

a) \(x^2+16=25\)

\(\Rightarrow x^2=25-16=9\Rightarrow x=\pm3\)

b) \(\left|\sqrt{x}-3\right|+3=9\left(đk:x\ge0\right)\)

\(\Rightarrow\left|\sqrt{x}-3\right|=9-3=6\)

\(\Rightarrow\left[{}\begin{matrix}\sqrt{x}-3=6\\\sqrt{x}-3=-6\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}\sqrt{x}=9\\\sqrt{x}=-3\left(VLý\right)\end{matrix}\right.\)\(\Rightarrow x=81\left(tm\right)\)