Question

rút gọn biểu thức B = \(\dfrac{\text{20x - 11}}{\text{x - 2012}}.\dfrac{\text{x(x - 2)}}{\text{1982x}^{\text{2}}+30}-\dfrac{20x-11}{1982x^2+30}:\dfrac{x-2012}{x\left(x-3\right)+2012}\)

Answer 1

\(B=\dfrac{\left(x^2-2x\right)\left(20x-11\right)}{\left(x-2012\right)\left(1982x^2+30\right)}-\dfrac{\left(20x-11\right)\left(x^2-3x+2012\right)}{\left(1982x^2+30\right)\left(x-2012\right)}\left(x\ne2012\right)\\ B=\dfrac{\left(20x-11\right)\left(x^2-2x-x^2+3x-2012\right)}{\left(x-2012\right)\left(1982x^2+30\right)} \\ B=\dfrac{\left(20x-11\right)\left(x-2012\right)}{\left(x-2012\right)\left(1982x^2+30\right)}=\dfrac{20x-11}{1982x^2+30}\)