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 )
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
\(A=\dfrac{1}{100}-\dfrac{1}{100.99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-....-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
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)\(\left|4x-0,2\right|=0,2\)
a) \(\left|2x-1\right|+\left|x+8\right|=4x\)
b) \(\left(\sqrt{x+1}\right)\left(\sqrt{x-3}\right)=0\)
c) \(3^x+3^{x+2}=2430\)
Tìm x : \(\dfrac{1}{x\left(x+1\right)}+\dfrac{1}{\left(x+1\right)\left(x+2\right)}+\dfrac{1}{\left(x+2\right)\left(x+3\right)}-\dfrac{1}{x}=\dfrac{1}{2010}\)
tìm x biết
1)\(\left(1-2x\right)^2=9\)
2)\(\left(x+5\right)^3=-64\)
3)\(\left(3x-5\right)^2=16\)
4) \(\left(x-1\right)^3=27\)
5)\(x^2+x=0\)
6)\(5^{x+2}=625\)
7) \(5-\left|3x-1\right|=3\)
8) \(\left|2x-1\right|+5=4\)
9)\(\left|\dfrac{1}{3}-x\right|-1=\dfrac{2}{3}\)
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) \(\left|\dfrac{3}{5}-\dfrac{1}{2}x\right|>\dfrac{2}{5}\)
Rút gọn :
M = \(\left|x-5\right|\) - 3.(2-x)-3
N = -8.(1-x)+\(\left|x+6\right|-\left|x+1\right|\)
Rút gọn :
M = \(\left|x-5\right|\) - 3.(2-x)-3
N = -8.(1-x)+\(\left|x+6\right|-\left|x+1\right|\)
