x trên vô nghiệm nhé

nếu 1x23 + 8x7 mà lại = 6x thì 

vô nghiệm 

yêu cầu chỉnh đề

`2x-2/3=1/2`

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

`2x=7/6`

`x=7/6:2=7/12`

\(2x-\dfrac{2}{3}=\dfrac{1}{2}\Leftrightarrow2x=\dfrac{2}{3}+\dfrac{1}{2}=\dfrac{7}{6}\Leftrightarrow x=\dfrac{7}{6}:2=\dfrac{7}{12}\)

là s???

mk chẳng hỉu j

mk nhak

Thanks

mợi người nhớ nha ko là mất điểm đó mình bị òi hê hê kb vs mk lun đi

a) \(215+x=400\)

\(\Rightarrow x=400-215\)

\(\Rightarrow x=185\)

b) \(12,5-2x=\dfrac{1}{5}\)

\(\Rightarrow2x=12,5-\dfrac{1}{5}\)

\(\Rightarrow2x=\dfrac{123}{10}\)

\(\Rightarrow x=\dfrac{123}{10}:2\)

\(\Rightarrow x=\dfrac{123}{20}\)

còn câu c d nhanh cậu ơi

1) \(x-36:18=12\)

\(\Leftrightarrow x-2=12\)

\(\Rightarrow x=14\)

2) \(x-38:12=12\)

\(\Leftrightarrow x-\frac{19}{6}=12\)

\(\Rightarrow x=\frac{91}{6}\)

3) \(\left(25+x\right)-20:4=35\)

\(\Leftrightarrow25+x-5=35\)

\(\Leftrightarrow x=15\)

4) \(720:\left[41-\left(2x-5\right)\right]+8=48\)

\(\Leftrightarrow41-2x+5=18\)

\(\Leftrightarrow2x=28\)

\(\Rightarrow x=14\)

5) \(5x-x+15=223\)

\(\Leftrightarrow4x=208\)

\(\Rightarrow x=52\)

6) \(7x-55=2x\)

\(\Leftrightarrow5x=55\)

\(\Rightarrow x=11\)

7) \(\left(x-10\right).11=0\)

\(\Leftrightarrow x-10=0\)

\(\Rightarrow x=10\)

Câu 2:

a: \(\frac{1}{\sqrt{11}+2\sqrt3}+\frac{1}{\sqrt{23+\sqrt{528}}}\)

\(=\frac{2\sqrt3-\sqrt{11}}{\left(2\sqrt3-\sqrt{11}\right)\left(2\sqrt3+\sqrt{11}\right)}+\frac{1}{\sqrt{23+2\cdot\sqrt{132}}}\)

\(=2\sqrt3-\sqrt{11}+\frac{1}{\sqrt{\left(2\sqrt3+\sqrt{11}\right)^2}}=2\sqrt3-\sqrt{11}+\frac{1}{2\sqrt3+\sqrt{11}}\)

\(=2\sqrt3-\sqrt{11}+2\sqrt3-\sqrt{11}=4\sqrt3-2\sqrt{11}\)

b: \(\frac{1}{\sqrt5-\sqrt3}-\frac{1}{\sqrt3-\sqrt2}-\frac{2}{\sqrt5+\sqrt2}\)

\(=\frac{\sqrt5+\sqrt3}{5-3}-\frac{\sqrt3+\sqrt2}{\left(\sqrt3-\sqrt2\right)\left(\sqrt3+\sqrt2\right)}-\frac{2\left(\sqrt5-\sqrt2\right)}{5-2}\)

\(=\frac12\cdot\sqrt5+\frac12\cdot\sqrt3-\sqrt3-\sqrt2-\frac23\left(\sqrt5-\sqrt2\right)\)

\(=\frac12\sqrt5-\frac12\cdot\sqrt3-\sqrt2-\frac23\cdot\sqrt5+\frac23\cdot\sqrt2=\frac{-1}{6}\sqrt5-\frac13\sqrt2-\frac12\sqrt3\)

c:

x>2

=>x-1>1

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

=>\(\sqrt{x-1}-1>0\)

\(\frac{1}{\sqrt{x+2\sqrt{x-1}}}+\frac{1}{\sqrt{x-2\sqrt{x-1}}}\)

\(=\frac{1}{\sqrt{x-1+2\cdot\sqrt{x-1}+1}}+\frac{1}{\sqrt{x-1-2\cdot\sqrt{x-1}\cdot1+1}}\)

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

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

Quá hay!!! giá như ai cũng thẳng thắn như bạn

a, 7 - x = 8 - (- 7)

    7 - x = 15    

         x = 7 - 15

         x = - 8

b, x - 8 = (- 3) - 8

    x - 8 = - 11

          x = -11 + 8

           x=-3

 câu cá

Hành động câu cá nhé !