a) \(\dfrac{x^2+4x+4}{x^2-4}\)
ĐKXĐ: \(x^2-4\ne0\Leftrightarrow x^2\ne4\Leftrightarrow x\ne\pm2\)
b) \(\dfrac{x^2+4x+4}{x^2-4}=\dfrac{x^2+2\cdot x\cdot2+2^2}{x^2-2^2}=\dfrac{\left(x+2\right)^2}{\left(x-2\right)\left(x+2\right)}=\dfrac{x+2}{x-2}\)
c) Ta có: \(\dfrac{x+2}{x-2}=1\Leftrightarrow x+2=x-2\Leftrightarrow4=0\) (vô nghiệm)
d) Ta có:
\(\dfrac{x+2}{x-2}=0\Leftrightarrow x+2=0\Leftrightarrow x=-2\left(ktm\right)\)
Đúng 1
Bình luận (0)
