\(=\dfrac{\left(3-x\right)\left(9+3x+x^2\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{-x^2-3x-9}{x+3}\)
\(=\dfrac{\left(3-x\right)\left(9+3x+x^2\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{-x^2-3x-9}{x+3}\)
\(\dfrac{x-4}{x-3}-\dfrac{5}{3+x}=-\dfrac{27}{9-x^2}\)
CM đẳng thức
\(\dfrac{x^{24}+x^{18}+x^{12}+x^6+1}{x^{27}+x^{24}+x^{21}+x^{18}+x^{15}+x^{12}+x^9+x^6+x^3+1}\)=\(\dfrac{1}{x^3+1}\)
Tính tổng sau:
a, \(\dfrac{-1}{x^2-x}+\dfrac{-1}{x^2-3x+2}+\dfrac{-1}{x^2-5x+6}+\dfrac{-1}{x^2-7x+12}+\dfrac{-1}{x^2-9x+20}+\dfrac{1}{x-5}\)
b, \(\dfrac{3}{x\left(x+3\right)}+\dfrac{3}{\left(x+3\right)\left(x+6\right)}+\dfrac{3}{\left(x+6\right)\left(x+9\right)}+\dfrac{1}{x+9}\)
Cho A= \(\dfrac{5}{x+3}-\dfrac{2}{3-x}-\dfrac{3x^2-2x-9}{x^2-9}\)
a. Rút gọn A?
b. Tính A khi I x-2 I = 1
Rút gọn phân thức
1). \(\dfrac{x^4-y^4}{y^3-x^3}\)
2). \(\dfrac{\left(2x-4\right)\left(x-3\right)}{\left(x-2\right)\left(3x^2-27\right)}\)
3). \(\dfrac{2x^3+x^2-2x-1}{x^3+2x^2-x-2}\)
ghi kq thôi cũng được ak
Rút gọn:
\(\left[1-\dfrac{x-3\sqrt{x}}{x-9}\right]:\left[\dfrac{\sqrt{x}-3}{2-\sqrt{x}}+\dfrac{\sqrt{x}-2}{3+\sqrt{x}}-\dfrac{9-x}{x+\sqrt{x}-6}\right]\)
Rút gọn phân thức :
a) \(\dfrac{x^4-y^4}{y^3-x^3}\)
b) \(\dfrac{\left(2x-4\right)\left(x-3\right)}{\left(x-2\right)\left(3x^2-27\right)}\)
c) \(\dfrac{2x^3+x^2-2x-1}{x^3+2x^2-x-2}\)
A = \(\left(\dfrac{2x^2}{x^{2^{ }}-9}+\dfrac{3}{x-3}-\dfrac{x}{x+3}\right).\dfrac{4}{5x+15}\)
a, Tìm điều kiện xác định của A
b, Rút gọn A
c, Tính giá trị của A tại x = 19
B1: Cho A = \(\dfrac{2x}{x-3}-\dfrac{3x^2+9}{x^2-9}+\dfrac{x}{x+3}\)
a. Rút gọn
b. Tìm x để A = \(\dfrac{2}{x-1}\)
B2: Cho A = \(\dfrac{x}{x-1}+\dfrac{2x^2}{x^2-1}-\dfrac{x}{x+1}\)
a. Rút gọn
b. Tìm x nguyên để A nguyên
rút gọn
\(A=\dfrac{3}{x+3}+\dfrac{1}{x-3}-\dfrac{18}{9-x^2}\)