Tìm GTNN của:
a) A = \(\left|x-1\right|+\left|x-2\right|+\left|x-3\right|+\left|x-4\right|+\left|x-5\right|\)
b) B = \(\left|x-1\right|+\left|x-2\right|+\left|x-3\right|+\left|x-4\right|+\left|x-5\right|+\left|x-6\right|\)
c) C = \(\left|x-1\right|+\left|x-2\right|+...+\left|x-n\right|\)( n là số lẻ )
d) D = \(\left|x-1\right|+\left|x-2\right|+...+\left|x-n\right|\)( n là số chẵn )
a,P=\(\left(x-4\right)^{\left(x-5\right)^{\left(x-6\right)^{\left(x+6\right)^{\left(x+5\right)}}}}\). Hãy tính giá trị của P với x=7?
b, \(\left(x-1\right)^{x+2}=\left(x-1\right)^{x+4}\)
c, P=\(\left(-1\right)^n.\left(-1\right)^{2n+1}.\left(-1\right)^{n+1}\)
Tìm x biết
a)\(\left(3x+\dfrac{1}{3}\right)\left(x-\dfrac{1}{2}\right)=0\)
b)\(\left(x-\dfrac{3}{2}\right)\left(2x+1\right)>0\)
c)\(\left(2-x\right)\left(\dfrac{4}{5}-x\right)< 0\)
d)\(\left(x-\dfrac{4}{7}\right):\left(x+\dfrac{1}{2}\right)>0\)
e)\(2\left(x+1\right)-\dfrac{1}{3}.\left(x-1\right)=\dfrac{2}{3}\)
k)\(\left|4x-0,2\right|=0,2\)
Cần giúp nhanh vs
Bài 1. Tìm x
a) \(\left|x+\dfrac{7}{4}\right|=\dfrac{1}{2}\)
b) \(\left|2x+1\right|-\dfrac{2}{5}=\dfrac{1}{3}\)
c) \(3x.\left(x+\dfrac{2}{3}\right)=0\)
d) \(x+\dfrac{1}{3}=\dfrac{2}{5}-\left(-\dfrac{1}{3}\right)\)
Bài 2. Tính nhanh
\(A=\dfrac{1}{100}-\dfrac{1}{100.99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-....-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
a) \(\left|2x-1\right|+\left|x+8\right|=4x\)
b) \(\left(\sqrt{x+1}\right)\left(\sqrt{x-3}\right)=0\)
c) \(3^x+3^{x+2}=2430\)
Bài 1 : Tìm GTLN, GTNN :
a, A= x-|x|
b, B= \(\dfrac{1}{\left|x-2\right|+3}\)
c, C= \(\dfrac{x-2}{\left|x\right|}\)
d, D=|x+5|+2-x
Bài 2 : Tìm x thuộc Q, biết :
a,\(\left|x+\dfrac{4}{15}\right|-\left|-3,75\right|=-\left|-2.15\right|\)
b,|x-1|=x-1
c,|x-1|+3x=1
d,2.|x|+3.|1-x|-5.|x-3|=0
Tìm x biết :
a) \(\left|2x+3\right|\) + x = 4
b) \(\left|5x-3\right|=\left|x-7\right|\)
c) \(2.\left|x-1\right|-3x=7\)
d) \(\left|\dfrac{3}{5}-\dfrac{1}{2}x\right|>\dfrac{2}{5}\)
Tìm giá trị nhỏ nhất của biểu thức A=\(\left|x-1\right|+2\left|x-2\right|+3\left|x-3\right|+4\left|x-4\right|\)
Tìm x : \(\dfrac{1}{x\left(x+1\right)}+\dfrac{1}{\left(x+1\right)\left(x+2\right)}+\dfrac{1}{\left(x+2\right)\left(x+3\right)}-\dfrac{1}{x}=\dfrac{1}{2010}\)
a) \(\left[\left(\dfrac{3}{5}\right)^2-\left(\dfrac{2}{5}\right)^2\right]\). X = \(\left(\dfrac{1}{5}\right)^3\)
b) \(1\dfrac{2}{5}.x+\dfrac{3}{7}=\dfrac{-4}{5}\)
c) \(\left(3x-2\right)^2=9\)
d) \(|x+\dfrac{1}{3}|-4=-1\)