Bài 1 : Tìm x biết
a/ x ( x + 4 ) + x + 4=0
b/ x ( x - 3) + 2x - 6 = 0
Bài 2 : rút gọn biểu thức
a/ \(\dfrac{6x^2y^2}{8xy^5}\) b/ \(\dfrac{3x^2-x}{9x^2-6x+1}\) e/ \(\dfrac{x^2+7x+12}{x^2+5x+6}\)
c/ \(\dfrac{x^2-9}{x^2+6x+9}\) d/ \(\dfrac{x^2+2x+1}{3x+3}\)
Bài 3 : thực hiện phép tính ( các mẫu thức đều không buông )
a/ \(\dfrac{15}{2x+6}+\dfrac{5x}{2x+6}\) b/ \(\dfrac{y}{2x^2-xy}+\dfrac{4x}{y^2-2xy}\) c/ \(\dfrac{x-1}{2x^2-2}-\dfrac{x+3}{4x+4}\)
d/ \(\dfrac{4y^2}{11x^4}.\left(-\dfrac{3x^2}{8y}\right)\) e/ \(\dfrac{5x+10}{4x-8}.\dfrac{4-2x}{x+2}\)
Bài 4 : Rút gọn và tính các giá trị của biểu thức
a/ \(\dfrac{3x^2-x}{9x^2-6x+1}\) tại x = \(\dfrac{1}{3}\) b/\(\dfrac{x^2-2xy+y^2-9}{x^2-xy+3x}\) Tại x = 2016 ; y = 3
Thực hiện các phép tính :
a) \(\left(\dfrac{9}{x^3-9x}+\dfrac{1}{x+3}\right):\left(\dfrac{x-3}{x^2+3x}-\dfrac{x}{3x+9}\right)\)
b) \(\left(\dfrac{2}{x-2}-\dfrac{2}{x+2}\right).\dfrac{x^2+4x+4}{8}\)
c) \(\left(\dfrac{3x}{1-3x}+\dfrac{2x}{3x+1}\right):\dfrac{6x^2+10x}{1-6x+9x^2}\)
d) \(\left(\dfrac{x}{x^2-25}-\dfrac{x-5}{x^2+5x}\right):\dfrac{2x-5}{x^2+5x}+\dfrac{x}{5-x}\)
e) \(\left(\dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+\dfrac{y}{x^2+y^2}\right):\left(\dfrac{1}{x-y}-\dfrac{2xy}{x^3-x^2y+xy^2-y^3}\right)\)
Thực hiện các phép tính sau:
a) \(\dfrac{3x^2-3y^2}{5xy}.\dfrac{15x^2y}{2y-2x}\)
b) \(\dfrac{4a^2-3a+5}{a^3-1}-\dfrac{1-2a}{a^2+a+1}-\dfrac{6}{a-1}\)
c) \(\dfrac{2a^3-2b^3}{3a+3b}.\dfrac{6a+6b}{a^2-2ab+b^2}\)
d) \(x^2+1-\dfrac{x^4+1}{x^2+1}\)
e) \(\dfrac{3}{2x+6}-\dfrac{x-6}{2x^2+6x}\)
quy đồng các phân thức sau
a,\(\dfrac{x+1}{x-1};\dfrac{x-1}{x+1};\dfrac{4}{1-x^2}\)
b,\(\dfrac{x^3}{x^3-3x^2y+3xy^2-y^3};\dfrac{x}{y^2xy}\)
c,\(\dfrac{4x}{x-2};\dfrac{3x}{x-2};\dfrac{12x}{x^2-4}\)
d,\(\dfrac{7}{x};\dfrac{x}{x+6};\dfrac{36}{x^2+6x}\)
giải các phương trình sau:
a)5-(x-6)=4(3-2x) b)\(\dfrac{3x+2}{2}-\dfrac{3x+1}{6}=2x+\dfrac{5}{3}\)
c)\(\dfrac{5x+2}{6}-\dfrac{8x-1}{3}=\dfrac{4x+2}{5}-5\) e)\(x-\dfrac{2x-5}{5}+\dfrac{x+8}{6}=7-\dfrac{x-1}{3}\)
d)x2-5x+6=0 f)(x2-4)-(x-2)(3-2x)=0 g)(2x+5)2=(x+2)2
Bài 1: Rút gon
a) B=\(\left(\dfrac{x}{3x-9}+\dfrac{2x-3}{3x-x^2}\right).\dfrac{3x^2-9x}{x^2+6x+9}\)
b) A=\(\left(\dfrac{x}{x^2-4}+\dfrac{2}{2-x}+\dfrac{1}{x+2}\right):\dfrac{1}{x+2}\)
rút gọn các biểu thức sau :
a, \(\left(\dfrac{3x}{1-3x}+\dfrac{2x}{3x+1}\right):\dfrac{6x^2+10x}{9x^2-6x+1}\)
b, \(\left(\dfrac{9}{x^3-9x}+\dfrac{1}{x+3}\right):\left(\dfrac{x-3}{x^2+3x}-\dfrac{x}{3x+9}\right)\)
c, \(\dfrac{1-x^2}{x}\left(\dfrac{x^2}{x+3}-1\right)+\dfrac{3x^2-14x+3x}{x^2+3x}\)
1. Thực hiện phép tính:
a.\(\dfrac{x}{x-3}\)+ \(\dfrac{9-6x}{x^{2^{ }}-3x}\)
b. \(\dfrac{6x^2}{6x-1}\)- \(\dfrac{x}{6x-1}\)
c. \(\dfrac{2}{x-y}\)+\(\dfrac{3}{x+y}\)+\(\dfrac{4x}{y^{2^{ }}-x^2}\)
d. \(\dfrac{x+1}{x^{2^{ }}-2x+1}\): \(\dfrac{x+1}{5x-5}\)
e. \(\dfrac{7x+6}{2x\left(x+7\right)}\) - \(\dfrac{3x+6}{2x^2+14x}\)
f. \(\dfrac{3x+21}{x^2-9}\)+\(\dfrac{2}{x+3}\)+\(\dfrac{3}{3-x}\)
g. (\(\dfrac{x}{x^2-36}\) - \(\dfrac{x-6}{x^{2^{ }}+6x}\)) : \(\dfrac{2x-6}{x^2+6x}\) + \(\dfrac{x}{6-x}\)