I.

1B

2C

3A

4D

5C

$nope$

bài kiểm tra toán thì bạn phải tự làm chứ

 1.This work needs…………….by ten today.

A.  finish                 B. finishing               C. to finish                 D. to have finished

Bị động với need thì ta chỉ cần dùng V-ing sau need thôi nhé

C vì need + to V

C. need + to inf: cần làm gì

915370

là kết quả

a)\(đkx\ge1,x\ne-1\)

\(\sqrt{\dfrac{x-1}{x+1}}=2\)

\(\Leftrightarrow\dfrac{x-1}{x+1}=4\)

\(\Leftrightarrow x-1=4x-4\)

\(\Leftrightarrow x=1\)(nhận)

Vậy S=\(\left\{1\right\}\)

c)đk\(25x^2-10x+1=\) \(\left(5x-1\right)^2\ge0\Leftrightarrow x\ge\dfrac{1}{5}\)

\(\sqrt{25x^2-10x+1}+2x=1\)

\(\Leftrightarrow\sqrt{\left(5x-1\right)^2}+2x=1\)

\(\Leftrightarrow5x-1+2x=1\)

\(\Leftrightarrow x=\dfrac{2}{7}\)(nhận)

Vậy S=\(\left\{\dfrac{2}{7}\right\}\)

c: Ta có: \(\sqrt{25x^2-10x+1}+2x=1\)

\(\Leftrightarrow\left|5x-1\right|=1-2x\)

\(\Leftrightarrow\left[{}\begin{matrix}5x-1=1-2x\left(x\ge\dfrac{1}{5}\right)\\5x-1=2x-1\left(x< \dfrac{1}{5}\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{7}\left(nhận\right)\\x=0\left(nhận\right)\end{matrix}\right.\)

\(\dfrac{2\left(5x+2\right)}{9}-1=\dfrac{4\left(33+2x\right)}{5}-\dfrac{5\left(1-11x\right)}{9}\)

\(\dfrac{10\left(5x+2\right)}{45}-\dfrac{45}{45}=\dfrac{36\left(33+2x\right)}{45}-\dfrac{25\left(1-11x\right)}{45}\)

\(50x-20-45=1188+72x-25+275x\)

\(50x-25=347x+1163\)

\(50x-347x=25+1163\)

\(-297x=1188\)

\(x=4\\ \)

d) 

\(\dfrac{2\left(x-4\right)}{3}+\dfrac{3x+13}{8}=\dfrac{2\left(2x-3\right)}{5}+12\)

\(\dfrac{80\left(x-4\right)}{120}+\dfrac{15\left(3x+13\right)}{120}=\dfrac{40\left(2x-3\right)}{120}+\dfrac{1440}{120}\)

\(80x-320+45x+195=80x-120+1440\)

\(125x-125=80x+1320\)

\(125x-80x=125+1320\)

\(45x=1445\)

   \(x=\dfrac{1445}{45}\) \(=\dfrac{289}{9}\)