Sau khi rút gọn phân thức \(\dfrac{80x^3-125x}{3\left(x-3\right)-\left(x-3\right)\left(8-4x\right)}\), ta có kết quả là
\(\dfrac{5x\left(4x+5\right)}{x-3}\).\(\dfrac{5x\left(4x-5\right)}{x-3}\).\(\dfrac{x\left(4x-5\right)}{x-3}\).\(\dfrac{5x\left(4x+5\right)}{3\left(x-3\right)}\).Hướng dẫn giải:\(\dfrac{80x^3-125x}{3\left(x-3\right)-\left(x-3\right)\left(8-4x\right)}\)\(=\dfrac{5x\left(16x^2-25\right)}{\left(x-3\right)\left[3-\left(8-4x\right)\right]}\)
\(=\dfrac{5x\left(4x-5\right)\left(4x+5\right)}{\left(x-3\right)\left(4x-5\right)}\)
\(=\dfrac{5x\left(4x+5\right)}{x-3}\).
