Khi thực hiện phép tính \(\dfrac{x^2+2x-3}{x^2+3x-10}:\dfrac{x^2+7x+12}{x^2-9x+14}\), ta có kết quả là
\(\dfrac{\left(x-1\right)\left(x-7\right)}{\left(x+5\right)\left(x+4\right)}\).\(\dfrac{x-7}{x+4}\).\(\dfrac{\left(x+1\right)\left(x+7\right)}{\left(x+5\right)\left(x+4\right)}\).\(\dfrac{\left(x+1\right)\left(x+7\right)}{\left(x-5\right)\left(x-4\right)}\).Hướng dẫn giải:\(\dfrac{x^2+2x-3}{x^2+3x-10}:\dfrac{x^2+7x+12}{x^2-9x+14}\)
\(=\dfrac{\left(x-1\right)\left(x+3\right)}{\left(x-2\right)\left(x+5\right)}.\dfrac{\left(x-2\right)\left(x-7\right)}{\left(x+3\right)\left(x+4\right)}\)
\(=\dfrac{\left(x-1\right)\left(x-7\right)}{\left(x+5\right)\left(x+4\right)}\).
