Question

Rút gọn các biểu thức sau:

a, P = (\(\dfrac{x}{x^2-36}-\dfrac{x-6}{x^2+6x}\) ) : \(\dfrac{2x-6}{x^2+6x}\) ( với x \(\ne\) -6; x\(\ne6;x\ne0;x\ne3\))

b, S = (\(\dfrac{2+x}{2-x}-\dfrac{4x^2}{x^2-4}-\dfrac{2-x}{2+x}\)) : \(\dfrac{3x-x^2}{2x^2-x^3}\) ( với \(x\ne0;x\ne-2;x\ne2\))

Answer 1

a) Tớ làm luôn nhé , không chép lại đề đâu

P = \(\left[\dfrac{x}{\left(x-6\right)\left(x+6\right)}-\dfrac{x-6}{x\left(x+6\right)}\right].\dfrac{x\left(x+6\right)}{2x-6}\)

ĐKXĐ : x # -6 ; x # 6 ; x # 0 ; x # 3 . Khi đó , ta có :

P = \(\left[\dfrac{x^2-\left(x-6\right)^2}{x\left(x-6\right)\left(x+6\right)}\right]\).\(\dfrac{x\left(x+6\right)}{2x-6}\)

P = \(\dfrac{x^2-x^2+12x-36}{x-6}.\dfrac{1}{2x-6}\)

P = \(\dfrac{6\left(2x-6\right)}{x-6}.\dfrac{1}{2x-6}=\dfrac{6}{x-6}\)

b) Tương tự