Cái này dễ mà bn
Ta có:\(A=\frac{x+2}{x+3}-\frac{5}{x^2+x-6}+\frac{1}{2-x}\left(ĐK:x\ne2;-3\right)\)
\(\Leftrightarrow A=\frac{x+2}{x+3}-\frac{5}{\left(x+3\right)\left(x-2\right)}-\frac{1}{x-2}\)
\(\Leftrightarrow A=\frac{x^2-4-5-x-3}{\left(x+3\right)\left(x-2\right)}\)
\(\Leftrightarrow A=\frac{x^2-x-12}{\left(x+3\right)\left(x-2\right)}=\frac{x+4}{x-2}\)
\(A=\frac{x+2}{x+3}-\frac{5}{x^2+x-6}+\frac{1}{2-x}\)
\(\Leftrightarrow A=\frac{x}{\left(2+3\right)}^2-\frac{5}{x^3-6}+\left(2-x\right)\)
\(\Leftrightarrow A=\frac{x}{5}^2-\frac{5}{x^3-6}+\left(2-x\right)\)
Ps: Không chắc đâu nhé! Thánh đây mới lớp 6 thôi
:v công nhận năm lớp 6 tôi trẩu vl!
ĐK: \(x\ne2;x\ne-3\)
\(A=\frac{x+2}{x+3}-\frac{5}{x^2+x-6}+\frac{1}{2-x}\)
\(=\frac{x+2}{x+3}-\frac{5}{\left(x+3\right)\left(x-2\right)}-\frac{1}{x-2}\)
\(=\frac{\left(x+2\right)\left(x-2\right)-5-x-3}{\left(x+3\right)\left(x-2\right)}\)
\(=\frac{x^2-4-5-x-3}{\left(x+3\right)\left(x+2\right)}=\frac{x^2-x-12}{\left(x+3\right)\left(x+2\right)}=\frac{\left(x-4\right)\left(x+3\right)}{\left(x+3\right)\left(x+2\right)}=\frac{x-4}{x+2}\)
