Violympic toán 8
Các câu hỏi tương tự
Chứng minh biểu thức sau ko phụ thuộc vào x:
\(A=x\left(x^2+x+1\right)-x^2\left(x+1\right)-x+5\)
\(B=x\left(2x+1\right)-x^2\left(x+2\right)+x^3-x+3\)
\(C=4\left(6-x\right)+x^2\left(2+3x\right)-x\left(5x-4\right)+3x^2\left(1-x\right)\)
\(D=5\left(3x^{n+1}-y^{n-1}\right)+3\left(x^{n+1}+5y^{n-1}\right)-5\left(3x^{n+1}+2y^{n-1}\right)\)
11 tháng 3 2020 lúc 15:52
a, (x-1)3 - x(x-1)2 = 5(2-x) - 11(x+2)
b, (x-2)3 + (3x-1)(3x+1) = (x+1)3
c, \(\frac{2x-1}{5}-\frac{x-2}{3}=\frac{x+7}{5}\)
d, \(\frac{2\left(x-3\right)}{7}+\frac{x-5}{3}=\frac{13x+4}{21}\)
e, \(\frac{\left(x+10\right)\left(x+4\right)}{12}-\frac{\left(x+4\right)\left(2-x\right)}{4}=\frac{\left(x+10\right)\left(x-2\right)}{3}\)
Giải các phương trình sau
a) frac{1}{x+1}-frac{5}{x-2}frac{15}{left(x+1right)left(2-xright)}
b) frac{1}{2x-3}-frac{3}{xleft(2x-3right)}frac{5}{x}
c) frac{6}{x-1}-frac{4}{x-3}frac{8}{2x-6}
d) frac{3}{left(x-1right)left(x-2right)}+frac{2}{left(x-3right)left(x-1right)}frac{1}{left(x-2right)left(x-3right)}
e) frac{1}{x-2}+frac{5}{x+1}frac{3}{2-x}
f) frac{5x}{2x+2}+1-frac{6}{x+1}
g) frac{x+1}{x-1}-frac{x-1}{x+1}frac{4}{x^2-1}
h) frac{3x}{x-2}-frac{x}{x-5}frac{3x}{left(x-2right)left(5-xright)}
Đọc tiếp
Giải các phương trình sau
a) \(\frac{1}{x+1}-\frac{5}{x-2}=\frac{15}{\left(x+1\right)\left(2-x\right)}\)
b) \(\frac{1}{2x-3}-\frac{3}{x\left(2x-3\right)}=\frac{5}{x}\)
c) \(\frac{6}{x-1}-\frac{4}{x-3}=\frac{8}{2x-6}\)
d) \(\frac{3}{\left(x-1\right)\left(x-2\right)}+\frac{2}{\left(x-3\right)\left(x-1\right)}=\frac{1}{\left(x-2\right)\left(x-3\right)}\)
e) \(\frac{1}{x-2}+\frac{5}{x+1}=\frac{3}{2-x}\)
f) \(\frac{5x}{2x+2}+1=-\frac{6}{x+1}\)
g) \(\frac{x+1}{x-1}-\frac{x-1}{x+1}=\frac{4}{x^2-1}\)
h) \(\frac{3x}{x-2}-\frac{x}{x-5}=\frac{3x}{\left(x-2\right)\left(5-x\right)}\)
Giải các phương trình sau
a) frac{7x-3}{x-1}frac{2}{3}
b) frac{2left(3-7xright)}{1+x}frac{1}{2}
c) frac{1}{x-2}+3frac{3-x}{x-2}
d) frac{8-x}{x-7}-8frac{1}{x-7}
e) frac{x+5}{x-5}-frac{x-5}{x+5}frac{20}{x^2-25}
f)frac{1}{x-1}+frac{2}{x+1}frac{x}{x^2-1}
g) frac{x}{2left(x-3right)}+frac{x}{2left(x+1right)}frac{2x}{left(x+1right)left(x-3right)}
h)5+frac{76}{x^2-16}frac{2x-1}{x+4}-frac{3x-1}{4-x}
i) frac{90}{x}-frac{36}{x-6}2
k) frac{1}{x}+frac{1}{x10}frac{1}{12}
l) frac{x+3}{x-3}-frac{1}{x...
Đọc tiếp
Giải các phương trình sau
a) \(\frac{7x-3}{x-1}=\frac{2}{3}\)
b) \(\frac{2\left(3-7x\right)}{1+x}=\frac{1}{2}\)
c) \(\frac{1}{x-2}+3=\frac{3-x}{x-2}\)
d) \(\frac{8-x}{x-7}-8=\frac{1}{x-7}\)
e) \(\frac{x+5}{x-5}-\frac{x-5}{x+5}=\frac{20}{x^2-25}\)
f)\(\frac{1}{x-1}+\frac{2}{x+1}=\frac{x}{x^2-1}\)
g) \(\frac{x}{2\left(x-3\right)}+\frac{x}{2\left(x+1\right)}=\frac{2x}{\left(x+1\right)\left(x-3\right)}\)
h)\(5+\frac{76}{x^2-16}=\frac{2x-1}{x+4}-\frac{3x-1}{4-x}\)
i) \(\frac{90}{x}-\frac{36}{x-6}=2\)
k) \(\frac{1}{x}+\frac{1}{x=10}=\frac{1}{12}\)
l) \(\frac{x+3}{x-3}-\frac{1}{x}=\frac{3}{x\left(x-3\right)}\)
m) \(\frac{3}{x+2}-\frac{2}{x-2}+\frac{8}{x^2-4}=0\)
n) \(\frac{3}{x+2}-\frac{2}{x-3}=\frac{8}{\left(x-3\right)\left(x+2\right)}\)
o)\(\frac{x}{2x+6}-\frac{x}{2x+2}=\frac{3x+2}{\left(x+1\right)\left(x+3\right)}\)
p) \(\frac{x}{x+1}-\frac{2x-3}{1-x}=\frac{3x^2+5}{x^2-1}\)
q) \(\frac{5}{x+7}+\frac{8}{2x+14}=\frac{3}{2}\)
r) \(\frac{x-1}{x}=\frac{1}{x+1}=\frac{2x-1}{x^2+x}\)
3) frac{1-x}{x+1}-frac{3+2x}{x+1}0
13) frac{x+2}{x}-frac{x^2+5x+4}{xleft(x+2right)}frac{x}{x+2}
14) frac{1}{x+1}-frac{5}{x-2}frac{20}{left(x+1right)left(2-xright)}
16) frac{x+5}{x-5}-frac{x-5}{x+5}frac{20}{x^2-25}
17) frac{3x+2}{3x-2}-frac{6}{2+3x}frac{9x^2}{9x^2-4}
18) frac{x-1}{x}+frac{1}{x+1}frac{2x-1}{2x^2+2}
19) frac{2}{x+1}-frac{3x+1}{left(x+1right)}frac{1}{left(x+1right)left(x-2right)}
20) frac{x+5}{3x-6}-frac{1}{2}frac{2x-3}{2x-4}
Đọc tiếp
3) \(\frac{1-x}{x+1}-\frac{3+2x}{x+1}=0\)
13) \(\frac{x+2}{x}-\frac{x^2+5x+4}{x\left(x+2\right)}=\frac{x}{x+2}\)
14) \(\frac{1}{x+1}-\frac{5}{x-2}=\frac{20}{\left(x+1\right)\left(2-x\right)}\)
16) \(\frac{x+5}{x-5}-\frac{x-5}{x+5}=\frac{20}{x^2-25}\)
17) \(\frac{3x+2}{3x-2}-\frac{6}{2+3x}=\frac{9x^2}{9x^2-4}\)
18) \(\frac{x-1}{x}+\frac{1}{x+1}=\frac{2x-1}{2x^2+2}\)
19) \(\frac{2}{x+1}-\frac{3x+1}{\left(x+1\right)}=\frac{1}{\left(x+1\right)\left(x-2\right)}\)
20) \(\frac{x+5}{3x-6}-\frac{1}{2}=\frac{2x-3}{2x-4}\)
giải pt sau
a)\(\left(x-2\right)\left(x-3\right)+2x=\left(x-2\right)^2-2\)
b) \(\left(x-1\right)^2+3x\left(x-1\right)+7=\left(2x-1\right)^2+5\left(x-3\right)\)
c)\(5\left(x^1-2x-1\right)+2\left(3x-2\right)=5\left(x+1\right)^2\)
d)\(\left(x-1\right)\left(x^2+x+1\right)-2x=x\left(x-1\right)\left(x+1\right)\)
Giải PT
\(\frac{1}{\left(x+1\right)\left(x+2\right)}+\frac{1}{\left(x+2\right)\left(x+3\right)}+\frac{1}{\left(x+3\right)\left(x+4\right)}+\frac{1}{\left(x+4\right)\left(x+5\right)}=\frac{1}{x+1}-403\)
1,Giải Pt
a,\(\frac{3x-7}{2}+\frac{x+1}{3}=-16\)
b,\(x-\frac{x+1}{3}=\frac{2x+1}{5}\)
c,\(\frac{7-3x}{12}+\frac{3}{4}=2\left(x-2\right)+\frac{5\left(5-2x\right)}{6}\)
e,\(\frac{3\left(x+3\right)}{4}+\frac{1}{2}=\frac{5x+9}{3}-\frac{7x-9}{4}\)
\(8\left(x+\frac{1}{x}\right)^2+4\left(x^2+\frac{1}{x^2}\right)^2-4\left(x^2+\frac{1}{x^2}\right)\left(x+\frac{1}{x}\right)^2=\left(x+4\right)^2\)
giải pt trên