`1/2 xx x +3/2 =7`

`=> 1/2 xx x = 7-3/2`

`=> 1/2 xx x = 14/2 -3/2`

`=> 1/2 xx x = 11/2`

`=> x= 11/2 :1/2`

`=> x=11/2 xx2`

`=> x= 22/2`

`=>x=11`

Vậy `x=11`

__

`3/2 xx x -2/7 xx(x-7/2)=18`

`=> 3/2 xx x -2/7x + 1=18`

`=> (3/2 -2/7 )x+ 1 =18`

`=> 17/14 x=18-1`

`=> 17/14x=17`

`=>x=17:17/14`

`=> x=17 xx 14/17`

`=>x=14`

a) \(\dfrac{1}{2}\times x+\dfrac{3}{2}=7\)

\(\dfrac{1}{2}\times x=7-\dfrac{3}{2}\)

\(\dfrac{1}{2}\times x=\dfrac{11}{2}\)

\(x=\dfrac{11}{2}\div\dfrac{1}{2}\\ x=\dfrac{11}{2}\times2\\ x=\dfrac{22}{2}=11\)

b) \(\dfrac{3}{2}\times x-\dfrac{2}{7}\times\left(x-\dfrac{7}{2}\right)=18\)

\(\dfrac{3}{2}\times x-\left(\dfrac{2}{7}x-1\right)=18\)

\(\dfrac{3}{2}\times x-\dfrac{2}{7}x+1=18\)

\(\dfrac{3}{2}x-\dfrac{2}{7}x+1=18\)

\(\dfrac{17}{14}x+1=18\)

\(\dfrac{17}{14}x=18-1\)

\(\dfrac{17}{14}x=17\)

\(x=17\div\dfrac{17}{14}\)

\(x=17\times\dfrac{14}{17}\)

\(x=14\)

a) \(\dfrac{1}{2}\times x+\dfrac{3}{2}=7\)

\(\Leftrightarrow\dfrac{1}{2}\times x=7-\dfrac{3}{2}\)

\(\Leftrightarrow\dfrac{1}{2}\times x=\dfrac{11}{2}\)

\(\Leftrightarrow x=\dfrac{11}{2}:\dfrac{1}{2}\)

\(\Leftrightarrow x=\dfrac{11}{2}\times\dfrac{2}{1}\)

\(\Rightarrow x=11\)

b) \(\dfrac{3}{2}\times x-\dfrac{2}{7}\times\left(x-\dfrac{7}{2}\right)=18\)

\(\Leftrightarrow\dfrac{3}{2}\times x-\dfrac{7}{2}\times x+1=18\)

\(\Leftrightarrow\left(\dfrac{3}{2}-\dfrac{7}{2}\right)\times x+1=18\)

\(\Leftrightarrow\dfrac{17}{14}\times x=18-1\)

\(\Leftrightarrow\dfrac{17}{14}\times x=17\)

\(\Leftrightarrow x=17:\dfrac{17}{14}\)

\(\Leftrightarrow x=17\times\dfrac{14}{17}\)

\(\Rightarrow x=14\)

Từ (1) rút ra được:  (*)

Thay (*) vào phương trình (2) ta được:

Thay  vào (*) ta được:

Vậy hệ phương trình có nghiệm 

b) Điều kiện xác định: x ≠ -1; y ≠ -1.

Đặt  , hệ phương trình trở thành:

Vậy hệ phương trình có nghiệm a

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

\(\Leftrightarrow\orbr{\begin{cases}x-1=2x-3\\x-1=-2x+3\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}3-1=2x-x\\x+2x=3+1\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=\frac{4}{3}\end{cases}}\)

LOZ CON MẸ CHÚNG MÀY NGU NHƯ ÓC LỢN SUỐT NGÀY KÊU ỤT ỊT

xoạc nhau đi

\(\dfrac{5}{4x}-\dfrac{3}{2}=\dfrac{3}{2}+\dfrac{x}{2}\\ \Leftrightarrow5-6x=6x+2x^2\\ \Leftrightarrow2x^2+12x-5=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-6+\sqrt{46}}{2}\\x=\dfrac{-6-\sqrt{46}}{2}\end{matrix}\right.\)

a) \(13\cdot\left(7-x\right)=26\)

\(\Rightarrow7-x=\dfrac{26}{13}\)

\(\Rightarrow7-x=2\)

\(\Rightarrow x=7-2\)

\(\Rightarrow x=5\)

b) \(\left(4x-18\right):3=2\)

\(\Rightarrow4x-18=2\cdot3\)

\(\Rightarrow4x-18=6\)

\(\Rightarrow4x=6+18\)

\(\Rightarrow4x=24\)

\(\Rightarrow x=24:4\)

\(\Rightarrow x=6\)

c) \(2\cdot x+98\cdot2022=98\cdot2023\)

\(\Rightarrow2\cdot x=98\cdot2023-98\cdot2022\)

\(\Rightarrow2\cdot x=98\cdot\left(2023-2022\right)\)

\(\Rightarrow2\cdot x=98\cdot1\)

\(\Rightarrow x=\dfrac{98}{2}\)

\(\Rightarrow x=49\)

d) \(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+...+\left(x+101\right)=?\)

Thiếu đề 

a) \(13.\left(7-x\right)=26\)

\(7-x=26:13\)

\(7-x=2\)

\(x=7-2\)

\(x=5\)

b) \(\left(4x-18\right):3=2\)

\(4x-18=6\)

\(4x=6+18\)

\(4x=24\)

\(x=24:4\)

\(x=6\)

Thành thiếu kìa bn