Violympic toán 8
Các câu hỏi tương tự
Bai 1: Cho bt
P=(\(\dfrac{x-2}{x^2-1}\)-\(\dfrac{x+2}{x^2+2x+1}\)).(\(\dfrac{1-x^2}{2}\))2
a, Rut gon P
b, Tim x de \(\dfrac{P-4}{5}\)=x
Bai 2:Chung minh bieu thuc A=\(\dfrac{3}{2}\)-\(\dfrac{x}{x^2+x+1}\) luon duong voi moi x
cho A=(\(\dfrac{x^{^2}-2x}{2x^2+8}\) - \(\dfrac{2x^2}{8-4x+2x^2-x^3}\) )(1-\(\dfrac{1}{x}\) -\(\dfrac{2}{x^2}\) )
a)/ rút gọn A
b) tìm x nguyên để A nguyên
Cộng các phân tử:
a)\(\dfrac{2x-3}{x}+\dfrac{1-x}{x+2}+\dfrac{4x}{x-1}\)
b)\(\dfrac{1}{1+x}+\dfrac{1}{x-1}+\dfrac{3x}{1-x^2}\)
c)\(\dfrac{x^3}{x+1}+\dfrac{x^2}{x-1}+\dfrac{1}{x+1}+\dfrac{1}{x-1}\)
d)\(\dfrac{2x+y}{2x^2-xy}+\dfrac{16x}{y^2-4x^2}+\dfrac{2x-y}{2x^2+xy}\)
Tính:
\(a,\dfrac{x+3}{2x-1}-\dfrac{x^2-5}{4x^2-4x+1}-\dfrac{2x^3+5x^2-x-1}{8x^3-12x^2+6x-1}\)
\(b,\dfrac{1}{1-x}+\dfrac{1}{1+x}+\dfrac{2}{1+x^2}+\dfrac{4}{1+x^4}+\dfrac{8}{1+x^8}+\dfrac{16}{1+x^{16}}\)
Bài 1: tính
a,\(\dfrac{1}{x^2-x}+\dfrac{2x}{4x^3}-\dfrac{1}{x^2+x+1}\)
b,\(\dfrac{1}{x^2-x+1}+1-\dfrac{x^2+2}{x^3+1}\)
c,\(\dfrac{1}{x\left(x-y\right)\left(x-z\right)}+\dfrac{1}{y\left(y-z\right)\left(y-x\right)}+\dfrac{1}{z\left(z-x\right)\left(z-y\right)}\)
Giải các phương trình sau :
a,\(\dfrac{2}{2x+1}-\dfrac{3}{2x-1}=\dfrac{4}{4x^2-1}\)
b,\(\dfrac{2x}{x+1}+\dfrac{18}{x^2+2x-3}=\dfrac{2x-5}{x+3}\)
c,\(\dfrac{1}{x-1}+\dfrac{2x^2-5}{x^3-1}=\dfrac{4}{x^2+x+1}\)
4.Giải phương trình
a) dfrac{x+5}{x-5}-dfrac{x-5}{x+5}dfrac{20}{x^2-25}
b)dfrac{1}{x-1}+dfrac{2}{x+1}dfrac{x}{x^2-1}
c)5+dfrac{76}{x^2-16}dfrac{2x-1}{x+4}-dfrac{3x-1}{4-x}
d)dfrac{90}{x}-dfrac{36}{x-6}2
e)dfrac{1}{x}+dfrac{1}{x+10}dfrac{1}{12}
f)dfrac{x+3}{x-3}-dfrac{1}{x}dfrac{3}{xleft(x-3right)}
g)dfrac{3}{x+2}-dfrac{2}{x-2}+dfrac{8}{x^2-4}0
h)dfrac{3}{x+2}-dfrac{2}{x-3}dfrac{8}{left(x-3right)left(x+2right)}
i)dfrac{x}{2x+6}-dfrac{x}{2x+2}dfrac{3x+2}{left(x+1right)left(x+3right)}
k)d...
Đọc tiếp
4.Giải phương trình
a) \(\dfrac{x+5}{x-5}-\dfrac{x-5}{x+5}=\dfrac{20}{x^2-25}\)
b)\(\dfrac{1}{x-1}+\dfrac{2}{x+1}=\dfrac{x}{x^2-1}\)
c)\(5+\dfrac{76}{x^2-16}=\dfrac{2x-1}{x+4}-\dfrac{3x-1}{4-x}\)
d)\(\dfrac{90}{x}-\dfrac{36}{x-6}=2\)
e)\(\dfrac{1}{x}+\dfrac{1}{x+10}=\dfrac{1}{12}\)
f)\(\dfrac{x+3}{x-3}-\dfrac{1}{x}=\dfrac{3}{x\left(x-3\right)}\)
g)\(\dfrac{3}{x+2}-\dfrac{2}{x-2}+\dfrac{8}{x^2-4}=0\)
h)\(\dfrac{3}{x+2}-\dfrac{2}{x-3}=\dfrac{8}{\left(x-3\right)\left(x+2\right)}\)
i)\(\dfrac{x}{2x+6}-\dfrac{x}{2x+2}=\dfrac{3x+2}{\left(x+1\right)\left(x+3\right)}\)
k)\(\dfrac{x}{x+1}-\dfrac{2x-3}{1-x}=\dfrac{3x^2+5}{x^2-1}\)
l)\(\dfrac{5}{x+7}+\dfrac{8}{2x+14}=\dfrac{3}{2}\)
m)\(\dfrac{x-1}{x}-\dfrac{1}{x+1}=\dfrac{2x-1}{x^2+x}\)
Cần gấp ạ
a,\(\dfrac{x^3+2x}{x^3+1}+\dfrac{2x}{x^2-x+1}+\dfrac{1}{x+1}\)
b,\(\dfrac{1-3x}{2x}+\dfrac{3x-2}{2x-1}+\dfrac{3x-2}{2x-4x^2}\)
Tính:
\(a,\dfrac{6}{x^2+4x}+\dfrac{3}{2x+8}\)
\(b,\dfrac{3-2x}{x^2-9}+\dfrac{1}{2x-6}\)