Giải phương trình:
a,\(\dfrac{x+1}{x^2+x+1}\)-\(\dfrac{x-1}{x^2-x+1}\)=\(\dfrac{3}{x.\left(x^4+x^2+1\right)}\)
b,\(\dfrac{1}{4x^2-12x+9}\)-\(\dfrac{3}{9-4x^2}=\dfrac{4}{4x^2+12x+9}\)
c,\(\dfrac{2}{\left(1-3y\right).\left(3y+11\right)}=\dfrac{1}{9y^2-y+1}-\dfrac{3}{\left(3y+11\right)^2}\)
d,\(\dfrac{x+5}{x-1}=\dfrac{x+1}{x-3}-\dfrac{8}{x^2-4x+3}\)
Giúp mk nha mn
d. ĐKXĐ: x khác 1, x khác 3
\(\dfrac{x+5}{x-1}=\dfrac{x+1}{\left(x-3\right)}-\dfrac{8}{x^2-4x+3}\)
\(\Leftrightarrow\dfrac{\left(x-3\right)\left(x+5\right)}{\left(x-1\right)\left(x-3\right)}=\dfrac{\left(x+1\right)\left(x-1\right)}{\left(x-1\right)\left(x-3\right)}-\dfrac{8}{\left(x-1\right)\left(x-3\right)}\) \(\Leftrightarrow x^2+2x-15=x^2-1-8\)
\(\Leftrightarrow2x-15+1+8=0\)
\(\Leftrightarrow2x-6=0\)
\(\Leftrightarrow x=3\) (loại)
Vậy pt vô nghiệm
