a) \(\Leftrightarrow x^2=\sqrt{4}\)

\(\Leftrightarrow x^2=2\Leftrightarrow x=\pm2\)

b) \(\Leftrightarrow\sqrt{\left(\dfrac{1}{2}x+1\right)^2}=9\)

\(\Leftrightarrow\left|\dfrac{1}{2}x+1\right|=9\)

\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x+1=9\\\dfrac{1}{2}x+1=-9\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=16\\x=-16\end{matrix}\right.\)

c) \(\Leftrightarrow\sqrt{2x}-4\sqrt{2x}+16\sqrt{2x}=52\left(đk:x\ge0\right)\)

\(\Leftrightarrow13\sqrt{2x}=52\Leftrightarrow\sqrt{2x}=4\Leftrightarrow2x=16\Leftrightarrow x=8\left(tm\right)\)

f: Ta có: \(\sqrt{\dfrac{50-25x}{4}}-8\sqrt{2-x}+\sqrt{18-9x}=-10\)

\(\Leftrightarrow\sqrt{2-x}\cdot\dfrac{5}{2}-8\sqrt{2-x}+3\sqrt{2-x}=-10\)

\(\Leftrightarrow\sqrt{2-x}=4\)

\(\Leftrightarrow2-x=16\)

hay x=-14

\(A=\dfrac{\sqrt{2}}{\sqrt{2}+1}+\dfrac{1}{3}\cdot3\sqrt{2}\)

\(=\sqrt{2}\left(\sqrt{2}-1\right)+\sqrt{2}=2\)

\(\Rightarrow2-4x=6-3x\\ \Rightarrow x=-4\)

\(\dfrac{2x-1}{3}=\dfrac{2-x}{-2}\)

\(\Rightarrow-2\left(2x-1\right)=3\left(2-x\right)\)

\(\Rightarrow-4x+2=6-3x\Rightarrow x=-4\)

Có đúng hông dậy mọi người

I.

1B

2C

3A

4D

5C

2. will visit/ am visiting

Tương lai đơn và tương lai gần (DHNB: tomorrow)

3. will have/ are having

Tương lai đơn và tương lai gần (DHNB: on the weekend)

4. produce 

Hiện tại đơn (DHNB: every year)

5. are wasting

Hiện tại tiếp diễn (DHNB: at the moment)

2 will visit (TLĐ: tomorrow)

3 will have (on the weekend: cuối tuần => TLĐ)

4 produce (HTĐ: every year)

5 are wasting (HTTD: at the moment)

Ta có: \(\left\{{}\begin{matrix}p+e+n=52\\p=e\\p+e-n=16\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}2n=36\\p=e\\p+e+n=52\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}n=18\\p=e=17\end{matrix}\right.\)

a. \(4\dfrac{1}{4}-2\dfrac{5}{8}+2\dfrac{3}{5}=\dfrac{17}{4}-\dfrac{21}{8}+\dfrac{13}{5}=\dfrac{169}{40}\)

b. \(4\dfrac{4}{9}:2\dfrac{2}{3}+3\dfrac{1}{6}=\dfrac{40}{9}:\dfrac{8}{3}+\dfrac{19}{6}=\dfrac{5}{3}+\dfrac{19}{6}=\dfrac{29}{6}\)

c. \(3\dfrac{1}{5}+2\dfrac{3}{5}-2\dfrac{4}{5}=\dfrac{16}{5}+\dfrac{13}{5}-\dfrac{14}{5}=\dfrac{16+13-14}{5}=\dfrac{15}{5}=3\)

d. \(5\dfrac{1}{7}-2\dfrac{4}{5}:1\dfrac{1}{5}=\dfrac{36}{7}-\dfrac{14}{5}:\dfrac{6}{5}=\dfrac{36}{7}-\dfrac{7}{3}=\dfrac{59}{21}\)

e. \(2\dfrac{3}{5}+1\dfrac{1}{4}.2\dfrac{2}{3}=\dfrac{13}{5}+\dfrac{5}{4}.\dfrac{8}{3}=\dfrac{13}{5}+\dfrac{10}{3}=\dfrac{89}{15}\)

g. \(4\dfrac{1}{3}.1\dfrac{1}{2}+5\dfrac{2}{7}=\dfrac{13}{3}.\dfrac{3}{2}+\dfrac{37}{7}=\dfrac{13}{2}+\dfrac{37}{7}=\dfrac{165}{14}\)