Đề bài : rút gọn các phân thức sau
\(c,\dfrac{2x+4}{x+2}=\dfrac{2\left(x+2\right)}{x+2}=2\\ \dfrac{3x-6}{x-2}=\dfrac{3\left(x-2\right)}{x-2}=3\\ \dfrac{x^2-25}{3x+15}=\dfrac{\left(x-5\right)\left(x+5\right)}{3\left(x+5\right)}=\dfrac{x-5}{3}\)
\(d,\dfrac{3x^2-3y^2}{2x^2+4xy+2y^2}=\dfrac{3\left(x^2-y^2\right)}{2\left(x^2+2xy+y^2\right)}=\dfrac{3\left(x-y\right)\left(x+y\right)}{2\left(x+y\right)^2}=\dfrac{3\left(x-y\right)}{2\left(x+y\right)}\\ \dfrac{2x^2-8x+8}{x^3-8}=\dfrac{2\left(x^2-4x+4\right)}{\left(x-2\right)\left(x^2+2x+4\right)}=\dfrac{2\left(x-2\right)^2}{\left(x-2\right)\left(x^2+2x+4\right)}=\dfrac{2\left(x-2\right)}{x^2+2x+4}\)
