Gọi 4 số liên tiếp lần lượt là a,b,c,d, ta có:

\(a,b,c,d\hept{\begin{cases}a=b-1\\a=c-2\\a=d-3\end{cases}}\Rightarrow a=\left(b+c+d\right)-6\)

\(\Rightarrow a=\frac{\left(406-6\right)}{4}=100\)

\(\Rightarrow\hept{\begin{cases}b=100+1=101\\c=100+2=102\\d=100+3=103\end{cases}}\)

Vậy 4 số liên tiếp đó lần lượt là: 100, 101, 102, 103

Bài 1: 

a) Ta có: \(4\left(x-5\right)+2x=-13\)

\(\Leftrightarrow6x-20=-13\)

\(\Leftrightarrow6x=7\)

hay \(x=\dfrac{7}{6}\)

b) Ta có: \(\dfrac{2x-1}{4}-3=\dfrac{1+x}{6}\)

\(\Leftrightarrow\dfrac{3\left(2x-1\right)}{12}-\dfrac{36}{12}=\dfrac{2\left(x+1\right)}{12}\)

Suy ra: \(6x-3-36=2x+2\)

\(\Leftrightarrow4x=41\)

hay \(x=\dfrac{41}{4}\)

c) ĐKXĐ: \(x\notin\left\{0;3\right\}\)

Ta có: \(\dfrac{x+3}{x-3}-\dfrac{8}{x}=\dfrac{18}{x^2-3x}\)

\(\Leftrightarrow\dfrac{x\left(x+3\right)}{x\left(x-3\right)}-\dfrac{8\left(x-3\right)}{x\left(x-3\right)}=\dfrac{18}{x\left(x-3\right)}\)

Suy ra: \(x^2+3x-8x+24-18=0\)

\(\Leftrightarrow x^2-5x+6=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\left(nhận\right)\\x=3\left(loại\right)\end{matrix}\right.\)

Vậy: S={2}

Bài 2: 

a) Ta có: 3x-11>5-x

\(\Leftrightarrow3x+x>5+11\)

\(\Leftrightarrow4x>16\)

hay x>4

Vậy: S={x|x>4}

b) Ta có: \(\dfrac{2x+1}{3}-\dfrac{3x-2}{6}\ge x+\dfrac{1}{6}\)

\(\Leftrightarrow\dfrac{2\left(2x+1\right)}{6}-\dfrac{3x-2}{6}\ge\dfrac{6x}{6}+\dfrac{1}{6}\)

Suy ra: \(4x+2-3x+2-6x-1\ge0\)

\(\Leftrightarrow-5x\ge-3\)

hay \(x< \dfrac{3}{5}\)

Vậy: S={x|\(x< \dfrac{3}{5}\)}

thi?

13. B

B

1 taking

2 comedian

3 organizing

4 poet

5 musician

6 designed 

7 taking

8 opera

Ex6

1 B

2 A

3 C

4 D

5 C

6 A

7 D

8 A

9 C

Bài 5: 

ĐKXĐ: \(\left\{{}\begin{matrix}x\ge0\\x\ne1\end{matrix}\right.\)

Ta có: \(G=\dfrac{x-\sqrt{x}}{\sqrt{x}-1}-\dfrac{x-1}{\sqrt{x}+1}\)

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

=1

chụp thiếu rồi!

a)a>1<32

1 as exciting as action film

2 the same as Salvador's

3 as well as my sister

4 the same

5 as long as we thought at first

Ex11

1 D 

2 D

3 D

4 D