a.) \(\frac{1}{x+1}-\frac{5}{x+2}=\frac{15}{\left(x+1\right)\left(2-x\right)}\)
\(\Leftrightarrow\)\(\frac{\left(x-1\right)\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}-\frac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\frac{-5x-2}{\left(x-2\right)\left(x+2\right)}\)
\(\Leftrightarrow\) \(x^2-2x-x+2-x^2-2x=-5x-2\)
\(\Leftrightarrow\) \(-2x-x-2x+5x=-2-2\)
\(\Leftrightarrow\) \(0x=-4\)(pt vô nghiệm )
\(\rightarrow\)S= \(\Phi\)
B) \(\frac{3x+2}{2}-\frac{3x+1}{6}=2x+\frac{5}{3}\)
\(\Leftrightarrow\frac{3\left(3x+2\right)}{6}-\frac{3x+1}{6}=6.2x+\frac{2.5}{6}\)
\(\Leftrightarrow9x+6-3x+1=12x+10\)
\(\Leftrightarrow9x-3x-12x=10-6-1\)
\(\Leftrightarrow-6x=3\)
\(\Leftrightarrow x=\frac{-1}{2}\)
\(\rightarrow S=\)\(\frac{-1}{2}\)
Câu b bạn sai r nhé. QUên đổi dấu r.
\(\frac{3x+2}{2}-\frac{3x+1}{6}=2x+\frac{5}{3}\)
\(\Rightarrow3\left(3x+2\right)-\left(3x+1\right)=12x+10\)
\(\Leftrightarrow9x+6-3x-1-12x=10\)
\(\Leftrightarrow-6x=10-6+1\)
\(\Leftrightarrow-6x=5\)
\(\Leftrightarrow x=-\frac{5}{6}\)
Vậy \(x=-\frac{5}{6}\)là nghiệm của phương trình
