\(\Leftrightarrow x\left(x-1\right)\left(x-2\right)\left(x+1\right)=24\)
\(\Leftrightarrow\left(x^2-x\right)\left(x^2-x-2\right)=24\)
\(\Leftrightarrow\left(x^2-x\right)^2-2\left(x^2-x\right)-24=0\)
\(\Leftrightarrow\left(x^2-x-6\right)\left(x^2-x+4\right)=0\)
=>(x-3)(x+2)=0
=>x=3 hoặc x=-2
cho A= \(\dfrac{x.\left(1-x^2\right)^2}{1+x^2}:\left[\left(\dfrac{1-x^3}{1-x}+x\right).\left(\dfrac{1+x^3}{1+x}-x\right)\right]\)
a) rút gọn
b.tìm A khi x = \(\dfrac{-1}{2}\)
c) tìm x để 2A =1
Bt thực hiện phép tính:
a/\(\dfrac{1}{x\left(x+1\right)}+\dfrac{1}{\left(x+1\right)\left(x+2\right)}+\dfrac{1}{\left(x+2\right)\left(x+3\right)}+...+\dfrac{1}{\left(x+2017\right)\left(x+2018\right)}\)
b/\(\dfrac{1}{x\left(x+2\right)\left(x+4\right)}+\dfrac{1}{\left(x+2\right)\left(x+4\right)\left(x+6\right)}+...+\dfrac{1}{\left(x+96\right)\left(x+98\right)\left(x+100\right)}\)
GIÚP MÌNH VỚI!!!!!! THỨ HAI THẦY KIỂM TRA RỒI!
Giair phương trình
\(8\left(x+\dfrac{1}{x}\right)+4\left(x^2+\dfrac{1}{x^2}\right)^2=\left(x+4\right)^2+4\left(x+\dfrac{1}{x}\right)^2\left(x^2+\dfrac{1}{x^2}\right).\)
giúp mik vs mn ơi
giúp mk với tứ tư mk phải nộp rùi
bài 1:
a, \(2x\left(3x^2-5x+3\right)\)
b, \(-2x\left(x^2+5x-3\right)\)
c, \(\dfrac{-1}{2}x\left(2x^3-4x+3\right)\)
bài 2:
a,\(\left(2x-1\right).\left(x^2-5-4\right)\)
b,\(-\left(5x-4\right).\left(2x+3\right)\)
c,\(\left(2x-y\right).\left(4x^2-2xy+y^2\right)\)
d,\(\left(3x-4\right).\left(x+4\right).\left(5-x\right).\left(2x^2+3x-1\right)\)
e,\(7\left(x-4\right)-\left(7x+3\right).\left(2x^2-x+4\right)\)
bài 3:
c/m rằng gtri của biểu thức ko phụ thuộc vào gtri của biến
a,\(x\left(3x+12\right)-\left(7x-20\right)+x^2\left(2x-3\right)-x\left(2x^2+5\right)\)
b,\(3\left(2x-1\right)-5\left(x-3\right)+6\left(3x-4\right)-19x\)
bài 4 :tìm x biết
a, \(3x+2\left(5-x\right)=0\)
b,\(x\left(2x-1\right).\left(x+5\right)-\left(2x^2+1\right).\left(x+4,5\right)=3,5\)
c,\(3x^2-3x\left(x-2\right)=36\)
d,\(\left(3x^2-x+1\right).\left(x-1\right)+x^2.\left(4-3x\right)=\dfrac{5}{2}\)
1.Cho B=\(\left(\dfrac{x-2}{x^2-5x+6}-\dfrac{x+3}{2-x}-\dfrac{x+2}{x-3}\right):\left(2-\dfrac{x}{x+1}\right)\)
a) Tìm đkxđ của B
b) Rút gọn B
c) Tìm x để B = 0
2. Cho C = \(\left(\dfrac{1}{x-1}-\dfrac{2x}{x^3-x^2+x-1}\right):\left(\dfrac{x^2+x}{x^3+x^2+x+1}+\dfrac{1}{x+1}\right)\)
a) Tìm đkxđ của C
b) Rút gọn C
c) Tìm x để C = \(\dfrac{2}{5}\)
d) Tìm x thuộc Z để giá trị C là số nguyên
Thực hiên phép tính:
a) \(\dfrac{1}{\left(a-b\right)\left(b-c\right)}+\dfrac{1}{\left(b-c\right)\left(c-a\right)}+\dfrac{1}{\left(c-a\right)\left(a-b\right)}\)
b) \(\dfrac{\left[a^2-\left(b+c\right)^2\right]\left(a+b-c\right)}{\left(a+b+c\right)\left(a^2+c^2-2ac-b^2\right)}\)
c) \(\dfrac{x-1}{x^3}-\dfrac{x+1}{x^3-x^2}+\dfrac{3}{x^3-2x^2+x}\)
d) \(\left[\dfrac{x^2-y^2}{xy}-\dfrac{1}{x+y}\left(\dfrac{x^2}{y}-\dfrac{y^2}{x}\right)\right]:\dfrac{x-y}{x}\)
Thực hiện phép tính:
\(\dfrac{1}{x\left(x+1\right)}\) + \(\dfrac{1}{\left(x+1\right)\left(x+2\right)}\) + \(\dfrac{1}{\left(x+2\right)\left(x+3\right)}\) + ... + \(\dfrac{1}{\left(x+2017\right)\left(x+2018\right)}\)
bài1: thực hiện phép tính
a,\(\frac{1}{\left(1-x\right).\left(2-x\right)}+\frac{2}{\left(2-x\right).\left(3-x\right)}+\frac{3}{\left(1-x\right).\left(x-3\right)}\)
b,\(\frac{x^2}{x+1}+\frac{2x}{^{ }x^2-1}-\frac{1}{1-x}+1\)
c,\(\frac{1}{x^3-x}-\frac{1}{\left(x-1\right).x}+\frac{2}{x^2-1}\)
Chứng minh đẳng thức :
a) \(\left(\dfrac{x^2-2x}{2x^2+8}-\dfrac{2x^2}{8-4x+2x^2-x^3}\right)\left(1-\dfrac{1}{x}-\dfrac{2}{x^2}\right)=\dfrac{x+1}{2x}\)
b) \(\left[\dfrac{2}{3x}-\dfrac{2}{x+1}\left(\dfrac{x+1}{3}-x-1\right)\right]:\dfrac{x-1}{x}=\dfrac{2x}{x-1}\)
c) \(\left[\dfrac{2}{\left(x+1\right)^3}.\left(\dfrac{1}{x}+1\right)+\dfrac{1}{x^2+2x+1}\left(\dfrac{1}{x^2}+1\right)\right]:\dfrac{x-1}{x^3}=\dfrac{x}{x-1}\)
