a: ĐKXĐ: \(x\notin\left\{3;-3\right\}\)
Bài 3:
\(c,ĐK:x\ne\pm3\\ d,P=\dfrac{3x-9+x+3+18}{\left(x-3\right)\left(x+3\right)}=\dfrac{4\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{4}{x-3}\\ e,P=4\Leftrightarrow x-3=1\Leftrightarrow x=4\left(tm\right)\)
Bài 4:
\(a,ĐK:x\ne-\dfrac{3}{2};x\ne-\dfrac{1}{2}\\ b,P=\dfrac{4x+2+6x+9-6x-5}{\left(2x+3\right)\left(2x+1\right)}=\dfrac{2\left(2x+3\right)}{\left(2x+3\right)\left(2x+1\right)}=\dfrac{2}{2x+1}\\ c,P=-1\Leftrightarrow2x+1=-2\Leftrightarrow x=-\dfrac{3}{2}\left(ktm\right)\Leftrightarrow x\in\varnothing\)
