Tìm x: a,\(\frac{x-1}{2011}+\frac{x-2}{2010}-\frac{x-3}{2009}=\frac{x-4}{2008}\)
b,\(\frac{1}{1\cdot3}+\frac{1}{3\cdot5}+\frac{1}{5\cdot7}+...+\frac{1}{\left(2x-1\right)\left(2x+1\right)}=\frac{49}{99}\)
Tìm x: \(\frac{1}{1.3}+\frac{1}{3.5}+...+\frac{1}{\left(2x-1\right)\left(2x+1\right)}=\frac{49}{99}\)
tính A=\(\frac{1}{2}\left(\frac{1}{1x3}\right)\left(\frac{1}{2x4}\right)\left(\frac{1}{3x5}\right)x....x\left(\frac{1}{2015x2017}\right)\)
Tính:
a) \(A=\left(1-\frac{1}{15}\right)x\left(1-\frac{1}{21}\right)x\left(1-\frac{1}{28}\right)x.........x\left(1-\frac{1}{1275}\right)\)
b) \(B=\left(1+\frac{1}{1x3}\right)x\left(1+\frac{1}{2x4}\right)x\left(1+\frac{1}{3x5}\right)x............x\left(1+\frac{1}{99x101}\right)\)
Bài 1:Tìm x
a)\(\left(5x+1\right)^2=\frac{36}{49}\)
b)\(\left(x-\frac{2}{9}\right)^3=\left(\frac{2}{3}\right)^6\)
c)\(\left(8x-1\right)^{2x+1}=5^{2x+1}\)
Tìm x biết:
a) \(\frac{1}{4}+\frac{1}{3}:2x=-5\)
b) \(\left(3x-\frac{1}{4}\right).\left(x+\frac{1}{2}\right)=0\)
c) \(|x+\frac{1}{5}|-\frac{1}{2}=\frac{9}{10}\)
d) \(\sqrt{0,81}.\left(\sqrt{x}+\sqrt{\frac{16}{49}}\right)=\frac{9}{10}\)
f) \(|\frac{1}{3}.\sqrt{x+1}-\frac{2}{9}|-\frac{1}{6}=\frac{1}{9}\)
Bài 1 : Tìm x biết :
a, \(\left|\frac{3}{2}x+\frac{1}{2}\right|=\left|4x-1\right|\)
b, \(\left|\frac{5}{4}x-\frac{7}{2}\right|-\left|\frac{5}{8}x+\frac{3}{5}\right|=0\)
c,\(\left|\frac{7}{5}x+\frac{2}{3}\right|=\left|\frac{4}{3}x-\frac{1}{4}\right|\)
Bài 2 : Tìm x biết :
a, | 2x - 5 | = x +1
b, | 3x - 2 | -1 = x
c, | 3x - 7 | = 2x + 1
d, | 2x-1 | +1 = x
Tìm x và y biết:
d)\(-1\frac{2}{3}-\left(\left|2x\right|+\frac{5}{6}\right)=\)\(-2\)e)\(\left(-\frac{1}{2}+\frac{1}{3}\right):\left|1-2x\right|-1\frac{1}{4}:\left(-\frac{5}{8}\right).\left(-\frac{1}{2}\right)^2=\frac{1}{3}\)
c)\(\left|2x-1\right|+\left|2y+1\right|+\left|2x-y\right|=0\)b)\(\left|2x-1\right|=2x-1\)
a)\(\left|x-3\right|=x+4\)
Tìm x, biết:
a)\(-3\frac{1}{2}+\frac{1}{3}.\left(x-1\right)=-1\frac{1}{3}:2\frac{1}{3}\)
b)\(\frac{x-1}{4}=\frac{x-2}{5}\)
c)\(\frac{x}{0,04}=\frac{0,09}{x}\)
d)\(4:\left(x-1\right)=\left(x-1\right):9\)
e)\(3\frac{1}{2}:x.\frac{1}{2}=5\frac{1}{3}:\frac{1}{2}.\frac{1}{5}\)
f)/2x-3/=5
g)\(\left(2x-\frac{1}{3}\right)^2=\left(1=3x\right)^2\)
h) \(\left(3-\frac{1}{2}:x\right)^2=\frac{1}{4}\)
i) \(\left(3-1\frac{1}{2}:x\right)^3=\frac{1}{8}\)