Question

Help me

1) \(\frac{1-6x}{x-2}+\frac{9x+4}{x+2}=\frac{x\left(3x-2\right)+1}{x^2-4}\)

2) \(\frac{x+1}{x-2}=\frac{1}{x-7}\)

3) \(\frac{7x-3}{x-1}=\frac{2}{3}\:\:\:\:\:\)

4) \(\frac{3-7x}{1+x}=\frac{1}{2}\)

Tks những bạn giúp mình nhé

Answer 1

1)\(ĐKXĐ:x\ne2;x\ne-2\)

đầu bài..

.\(\Rightarrow\left(1-6x\right)\left(x+2\right)+\left(9x+4\right)\left(x-2\right)=x\left(3x-2\right)+1\)

\(\Leftrightarrow-6x^2-11x+2+9x^2-14x-8=3x^2-2x+1\)

\(\Leftrightarrow-23x=7\Leftrightarrow x=-\frac{7}{23}\)(nhận)

Vậy...........

2).......\(ĐKXĐ:x\ne2;x\ne7\)

\(\Rightarrow\left(x+1\right)\left(x-7\right)=x-2\)

\(\Leftrightarrow x^2-6x-7=x-2\)

\(\Leftrightarrow x^2-7x-5=0\)..............

Vậy........

3)ĐKXĐ:\(x\ne1\)

.........\(\Rightarrow3\left(7x-3\right)=2\left(x-1\right)\)

\(\Leftrightarrow21x-9=2x-2\)

\(\Leftrightarrow19x=7\Leftrightarrow x=\frac{7}{19}\)(nhận)

4)ĐKXĐ:\(x\ne-1\)

.........\(\Rightarrow2\left(3-7x\right)=1+x\)

\(\Leftrightarrow6-14x=1+x\)

\(\Leftrightarrow15x=5\Leftrightarrow x=\frac{1}{3}\)(nhận)

Vậy...................