\(\left|x-5\right|>7\Leftrightarrow\left[{}\begin{matrix}x-5>7\\x-5< -7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x>12\\x< -2\end{matrix}\right.\)
Tìm x, biết:
a) \(\frac{x+5}{5}+\frac{x+5}{7}+\frac{x+5}{9}=\frac{x+5}{11}+\frac{x+5}{13}\)
b)\(\frac{x+2}{100}+\frac{x+3}{99}+\frac{x+4}{98}=\frac{x+5}{97}+\frac{x+6}{96}+\frac{x+7}{95}\)
c) (x+2) - (x+3) >0
d)\(\left(x-5\right)\left(x+\frac{7}{3}\right)\ge0\)
\(25\dfrac{3}{5}\)x\(\dfrac{7}{12}\)-\(31\dfrac{3}{5}\)x\(\dfrac{7}{12}\)
\(\left(3\dfrac{5}{7}x-1\dfrac{5}{7}x\right)-\dfrac{1}{3}=\dfrac{2}{3}\)
Chứng minh rằng :
1. x+7>x+5 2. x-3<x+7 3. x+10>x+7
3.a: -3/2-2x+3/4=-4
b: (-2/3.x-3/5).(3/-2-10/3)=2/5
c: x/2-(3x/5-13/5)=-(7/5+7/10x)
d: (3/2-5/11-3/13).(2x-2)=(-3/4+5/22+3/26)
e: 2/3x-3/12=4/5-(7/x-2)
a)1/2x+3/5x=-33/22
b) (2/3x -4/7).(1/2+-3/7:x)=0
c) (4/5-2x).(1/3+3/5:x)=0
: |3 + 2x| = 7. Giá trị của x là
A. x = 2 B. x = -5 C. x = 2 hoặc x= -5 D. x = -2
a)\(\dfrac{\left(x+\dfrac{3}{4}\right)\cdot\dfrac{7}{2}-\dfrac{1}{6}}{-\left(\dfrac{4}{5}+\dfrac{1}{3}\right)\cdot\dfrac{1}{2}+1}=2\dfrac{33}{52}\)
b)\(\dfrac{\left(5-\dfrac{2}{7}\right)\cdot\dfrac{7}{9}:\dfrac{3}{5}}{\left(3x-\dfrac{5}{6}\right):\dfrac{1}{7}}=5\dfrac{5}{21}\)
Bài 7: Tìm X
Tìm x biết:
a)\(\frac{3}{5}\times x-\frac{1}{5}=\frac{4}{5}\)
b)\(\frac{4}{7}+\frac{5}{7}\div x=1\)
c)\(\frac{-12}{7}\times\left(\frac{3}{4}-x\right)\times\frac{1}{4}=-1\)
d)\(x\div\frac{17}{8}=\frac{-2}{5}\times\frac{-9}{17}+3\)
Tìm x biết :
1) \(\dfrac{-7}{x+1}=\dfrac{-x-1}{\dfrac{4}{7}}\)
2) \(\dfrac{x-3}{x+5}=\dfrac{5}{7}\)
3) \(\dfrac{x+1}{2x+1}=\dfrac{0,5x+2}{x+3}\)
4) \(\dfrac{3x+2}{5x+7}=\dfrac{3x-1}{5x+1}\)
