a: =>(x-2)(3x+1)-(x-2)(x+2)=0

=>(x-2)(3x+1-x-2)=0

=>(x-2)(2x-1)=0

=>x=1/2 hoặc x=2

b: =>3(x-1)+4(x+1)=6(x-1)

=>3x-3+4x+4=6x-6

=>7x+1=6x-6

=>x=-7

c: =>x(x-3)-(x+2)(x+3)+16=0

=>x^2-3x-x^2-5x-6+16=0

=>10-8x=0

=>x=5/4

- Bạn ơi, bạn viết rõ đề ra được k ạ?

\(\frac{5}{6}=\frac{x-1}{x}\left(đk:x\ne0\right)\)

\(< =>5x=6\left(x-1\right)< =>5x=6x-6\)

\(< =>6x-5x=6< =>x=6\left(tmđk\right)\)

\(\frac{1}{2}=\frac{x+1}{3x}\left(đk:x\ne0\right)\)

\(< =>3x=2\left(x+1\right)< =>3x=2x+2\)

\(< =>3x-2x=2< =>x=2\left(tmđk\right)\)

\(\frac{3}{x+2}=\frac{5}{2x+1}\left(đk:x\ne-2;-\frac{1}{2}\right)\)

\(< =>3\left(2x+1\right)=5\left(x+2\right)< =>6x+3=5x+10\)

\(< =>6x-5x=10-3< =>x=7\left(tmđk\right)\)

\(\frac{5}{8x-2}=-\frac{4}{7-x}\left(đk:x\ne\frac{1}{4};7\right)\)

\(< =>\frac{5}{8x-2}=\frac{4}{x-7}< =>5\left(x-7\right)=4\left(8x-2\right)\)

\(< =>5x-35=32x-8< =>32x-5x=-35+8\)

\(< =>27x=-27< =>x=-1\)

\(\frac{4}{3}=\frac{2x-1}{3}< =>4.3=\left(2x-1\right).3\)

\(< =>12=6x-3< =>6x=12+3\)

\(< =>6x=15< =>x=\frac{15}{6}=\frac{5}{2}\)

\(\frac{2x-1}{3}=\frac{3x+1}{4}< =>4\left(2x-1\right)=3\left(3x+1\right)\)

\(< =>8x-4=9x+3< =>9x-8x=-4-3\)

\(< =>9x-8x=-7< =>x=-7\)

\(\frac{4}{x+2}=\frac{7}{3x+1}\left(đk:x\ne-2;-\frac{1}{3}\right)\)

\(< =>4\left(3x+1\right)=7\left(x+2\right)< =>12x+4=7x+14\)

\(< =>12x-7x=14-4< =>5x=10\)

\(< =>x=\frac{10}{5}=2\left(tmđk\right)\)

\(-\frac{3}{x+1}=\frac{4}{2-2x}\left(đk:x\ne-1;1\right)\)

\(< =>-3\left(2-2x\right)=4\left(x+1\right)< =>-6+6x=4x+4\)

\(< =>6x-4x=4+6< =>2x=10\)

\(< =>x=\frac{10}{2}=5\left(tmđk\right)\)

\(\frac{x+1}{3}=\frac{3}{x+1}\left(đk:x\ne-1\right)\)

\(< =>\left(x+1\right)\left(x+1\right)=3.3\)

\(< =>x^2+2x+1=9< =>x^2+2x+1-9=0\)

\(< =>x^2+2x-8=0< =>x^2-2x+4x-8=0\)

\(< =>x\left(x-2\right)+4\left(x-2\right)=0< =>\left(x+4\right)\left(x-2\right)=0\)

\(< =>\orbr{\begin{cases}x+4=0\\x-2=0\end{cases}< =>\orbr{\begin{cases}x=-4\\x=2\end{cases}}}\left(tmđk\right)\)

a, \(\frac{5}{6}=\frac{x-1}{x}\Leftrightarrow5x=6x-6\Leftrightarrow-x=-6\Leftrightarrow x=6\)

b, \(\frac{1}{2}=\frac{x+1}{3x}\Leftrightarrow3x=2x+2\Leftrightarrow x=2\)

c, \(\frac{3}{x+2}=\frac{5}{2x+1}\)ĐKXĐ : \(x\ne-2;-\frac{1}{2}\)

\(\Leftrightarrow6x+3=5x+10\Leftrightarrow x=7\)

1 a

2c

3b

4d

5c

6c

a: =>3(3x-7)+2(x+1)=-96

=>9x-21+2x+2=-96

=>11x-19=-96

=>11x=-96+19=-75

=>x=-75/11

b: \(x-\dfrac{x+1}{3}=\dfrac{2x+1}{5}\)

=>15x-5(x+1)=3(2x+1)

=>15x-5x-5=6x+3

=>10x-5=6x+3

=>4x=8

=>x=2

a)

\(\dfrac{3x-7}{2}+\dfrac{x+1}{3}=-16\)

\(< =>9x-21+2x+2=-96\)

\(< =>9x+2x=-96+21-2\\ < =>11x=-77\\ < =>x=-7\)

b)

\(\dfrac{x-x+1}{3}=\dfrac{2x+1}{5}\\ < =>5=6x+3\\ < =>6x=5-3\\ < =>6x=2\\ < =>x=\dfrac{1}{3}\)

\(a,\dfrac{3x-7}{2}+\dfrac{x+1}{3}=-16\\ \Rightarrow3\left(3x-7\right)+2\left(x+1\right)=2.3.\left(-16\right)\\ \Rightarrow9x-21+2x+2=-96\\ \Rightarrow11x-19=-96\\ \Rightarrow11x=-77\\ \Rightarrow x=-7\\ b,x-\dfrac{x+1}{3}=\dfrac{2x+1}{5}\\ \Rightarrow15x-5.\left(x+1\right)=3.\left(2x+1\right)\\\Rightarrow 15x-5x-5=6x+3\\ \Rightarrow10x-6x=3+5\\ \Rightarrow4x=8\\ \Rightarrow x=2\)

c: \(\dfrac{3x+5}{x^2-5x}+\dfrac{25-x}{25-5x}\)

\(=\dfrac{3x+5}{x\left(x-5\right)}+\dfrac{x-25}{5\left(x-5\right)}\)

\(=\dfrac{15x+25+x^2-25x}{5x\left(x-5\right)}=\dfrac{x^2-10x+25}{5x\left(x-5\right)}=\dfrac{x-5}{5x}\)

e: \(\dfrac{4x^2-3x+17}{x^3-1}+\dfrac{2x-1}{x^2+x+1}+\dfrac{6}{1-x}\)

\(=\dfrac{4x^2-3x+17+\left(2x-1\right)\left(x-1\right)-6x^2-6x-6}{\left(x-1\right)\left(x^2+x+1\right)}\)

\(=\dfrac{-2x^2-9x+11+2x^2-3x+1}{\left(x-1\right)\left(x^2+x+1\right)}\)

\(=\dfrac{-12\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}=\dfrac{-12}{x^2+x+1}\)

giup mk vs ạ !!!

`a,5x-2=3x+1`

`<=>5x-3x=1+2`

`<=>2x=3`

`<=>x=3/2`

Vậy `x=3/2`

`b,(x+5)(2x-3)=0`

`<=>` $\left[ \begin{array}{l}x+5=0\\2x-3=0\end{array} \right.$

`<=>` $\left[ \begin{array}{l}x=\dfrac{3}{2}\\x=-5\end{array} \right.$

Vậy `S={-5,3/2}`

Dẫn khí CO dư qua ống sứ chứa 20(g) FexOy và PbO cho đến khi phản ứng kết thúc, thu được chất rắn A và khí B. Cho A vào dung dịch HCl dư, thấy thoát ra 4,48(l) khí ở đktc. Dẫn khí B vào dung dịch Ca(OH)2 dư thu được 35(g) kết tủa. Lập CT FexOy                

giup minh giai voi