Violympic toán 8
Các câu hỏi tương tự
Giải các phương trình sau:
1. \(a,\dfrac{6}{x-1}-\dfrac{4}{x-3}=\dfrac{8}{2x-6}\)
\(b,\dfrac{1}{x-2}+\dfrac{5}{x+1}=\dfrac{3}{2-x}\)
\(c,\dfrac{3x}{x-2}-\dfrac{x}{x-5}=\dfrac{3x}{\left(x-2\right)\left(5-x\right)}\)
2. \(a,\left(x+2\right)\left(3-4x\right)=x^2+4x+4\)
\(b,2x^2-6x+1\)
1) Cho P left(dfrac{4x-x^3}{1-4x^2}-xright):left(dfrac{4x^2-x^4}{1-x^2}+1right)
a) rút gọn b) tìm x để P 0
2) Cho Q left(dfrac{x}{x^2-3x+9}-dfrac{11}{x^3+27}+dfrac{1}{x+3}right):dfrac{x^2-1}{x+3}
a) rút gọn b) tìm GTLN
3) Cho A dfrac{1}{left(x-yright)^3}left(dfrac{1}{x^3}-dfrac{1}{y^3}right)+dfrac{3}{left(x-yright)^4}left(dfrac{1}{x^2}+dfrac{1}{y^2}right)+dfrac{6}{left(x-yright)^5}left(dfrac{1}{x}+dfrac{1}{y}right)
chứng minh A là lập phương một số hữu tỉ
Đọc tiếp
1) Cho P = \(\left(\dfrac{4x-x^3}{1-4x^2}-x\right):\left(\dfrac{4x^2-x^4}{1-x^2}+1\right)\)
a) rút gọn b) tìm x để P > 0
2) Cho Q = \(\left(\dfrac{x}{x^2-3x+9}-\dfrac{11}{x^3+27}+\dfrac{1}{x+3}\right):\dfrac{x^2-1}{x+3}\)
a) rút gọn b) tìm GTLN
3) Cho A = \(\dfrac{1}{\left(x-y\right)^3}\left(\dfrac{1}{x^3}-\dfrac{1}{y^3}\right)+\dfrac{3}{\left(x-y\right)^4}\left(\dfrac{1}{x^2}+\dfrac{1}{y^2}\right)+\dfrac{6}{\left(x-y\right)^5}\left(\dfrac{1}{x}+\dfrac{1}{y}\right)\)
chứng minh A là lập phương một số hữu tỉ
1) left(dfrac{-3}{4}right)^{3x+1}dfrac{81}{256} 6) left(8x-1right)^{2n-4}5^{2n-4}
2) 172.x^2-dfrac{7^9}{98^3}dfrac{1}{2^3} 7) left(dfrac{1}{2x}-5right)^{20}+left(y^2-dfrac{1}{4}right)^{10}0
3) left(x-dfrac{2}{9}right)^3left(dfrac{2}{3}right)^6
4) left(x+2right)^2+left(y-dfrac{1}{10}right)^20
5) left(x-7right)^{n+1}-left(x-7right)^{n+11}0
Giúp mk với!!...
Đọc tiếp
1) \(\left(\dfrac{-3}{4}\right)^{3x+1}=\dfrac{81}{256}\) 6) \(\left(8x-1\right)^{2n-4}=5^{2n-4}\)
2) \(172.x^2-\dfrac{7^9}{98^3}=\dfrac{1}{2^3}\) 7) \(\left(\dfrac{1}{2x}-5\right)^{20}+\left(y^2-\dfrac{1}{4}\right)^{10}=0\)
3) \(\left(x-\dfrac{2}{9}\right)^3=\left(\dfrac{2}{3}\right)^6\)
4) \(\left(x+2\right)^2+\left(y-\dfrac{1}{10}\right)^2=0\)
5) \(\left(x-7\right)^{n+1}-\left(x-7\right)^{n+11}=0\)
Giúp mk với!!!!!
Giải phương trình:
b) \(\dfrac{7}{2}-\left(\dfrac{x}{5}-\dfrac{1}{4}\right)=\dfrac{9}{2}\)
c) (x+2) . (x-5). (x-6) (x+3) = 180
d) \(x-\dfrac{\dfrac{x}{2}-\dfrac{3+x}{4}}{2}=\dfrac{2x-\dfrac{10-7x}{3}}{2}-x-1\)
e) \(\left(\dfrac{1}{1.101}+\dfrac{1}{2.102}+........+\dfrac{1}{10.110}\right).\left(x-3\right)=\dfrac{1}{1.11}+\dfrac{1}{2.12}+.......+\dfrac{1}{100.110}\)
giải phương trình
1)\(\dfrac{1}{x^2}+\dfrac{1}{\left(x+2\right)^2}=\dfrac{10}{9}\)
2) \(x^2+\dfrac{25x^2}{\left(x+5\right)^5}=11\)
3) x\(\left(\dfrac{5-x}{x+1}\right)\left(x+\dfrac{5-x}{x+1}\right)=6\)
4) \(\left(\dfrac{x}{x+1}\right)^2\left(\dfrac{x}{x-1}\right)^2=90\)
( \(\dfrac{x+1}{2\left(x-1\right)}+\dfrac{3}{x^2-1}-\dfrac{x+3}{2x+2}\) ). \(\dfrac{4x^2-4}{5}\)
\(\dfrac{x}{x-3}-\dfrac{x^2+3x}{2x+3}.\left(\dfrac{x+3}{x^2-3x}-\dfrac{x}{x^2-9}\right)\)
\(\left(\dfrac{x+1}{x}\right)^2:\left(\dfrac{x^2+3}{x^2}+\dfrac{2}{x+1}.\left(\dfrac{1}{x}+1\right)\right)\)
giai phuong trinh : \(\dfrac{4x^2+14}{x^2+6}-\dfrac{5}{x^2+1}=\dfrac{7}{x^2+3}+\dfrac{9}{x^2+5}\)
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
tìm nghiệm của phân thức viết dưới dạng phân số
a.dfrac{4}{left(2+dfrac{2}{1+dfrac{4}{5}}right)x-left(1-dfrac{4}{2+dfrac{1}{1+dfrac{7}{8}}}right)}+dfrac{1}{2+dfrac{1}{3+dfrac{1}{4}}}
4+dfrac{2}{1+dfrac{8}{9}}
b.
dfrac{1}{2+dfrac{3}{4+dfrac{5}{6+dfrac{7}{8}}}}dfrac{1}{3+dfrac{2}{5+dfrac{3}{7+dfrac{4}{9}}}}+x.left(4+dfrac{1}{1+dfrac{1}{1+dfrac{1}{2}}}right)
(giải bằng máy tính casio )
Đọc tiếp
tìm nghiệm của phân thức viết dưới dạng phân số
a.\(\dfrac{4}{\left(2+\dfrac{2}{1+\dfrac{4}{5}}\right)x-\left(1-\dfrac{4}{2+\dfrac{1}{1+\dfrac{7}{8}}}\right)}+\dfrac{1}{2+\dfrac{1}{3+\dfrac{1}{4}}}\)
= \(4+\dfrac{2}{1+\dfrac{8}{9}}\)
b.
\(\dfrac{1}{2+\dfrac{3}{4+\dfrac{5}{6+\dfrac{7}{8}}}}=\dfrac{1}{3+\dfrac{2}{5+\dfrac{3}{7+\dfrac{4}{9}}}}+x.\left(4+\dfrac{1}{1+\dfrac{1}{1+\dfrac{1}{2}}}\right)\)
(giải bằng máy tính casio )