tìm x biết
a,\(\frac{1}{100}< \frac{x}{110}< \frac{1}{50}\)
b,\(\frac{123}{1000}< \frac{x}{2008}< \frac{124}{1000}\)
tìm số tự nhiên x biết
a.\(\frac{1}{100}< \frac{x}{110}< \frac{1}{50}\)
b.\(\frac{123}{1000}< \frac{x}{2008}< \frac{124}{1000}\)
\(\frac{1}{10}< \frac{x}{11}< \frac{1}{5}\Rightarrow\frac{11}{110}< \frac{x}{110}< \frac{22}{110}\Rightarrow x\in12;...;21\)
1.
a) \(A=\frac{\left(\frac{2018}{1}-1\right)\left(\frac{2018}{2}-1\right)...\left(\frac{2018}{1000}-1\right)}{\left(\frac{1000}{1}+1\right)\left(\frac{1000}{2}+1\right)...\left(\frac{1000}{1007}+1\right)}\)
b) Tìm x biết 378% của x kém A 55 đơn vị.
2. Tìm a, b, c sao cho : \(\frac{\overline{ab}.\overline{bc}.\overline{ca}}{\overline{ab}+\overline{bc}+\overline{ca}}=\frac{3321}{11}\)
Tìm x biết :\(\frac{x+1}{125}+\frac{x+2}{124}+\frac{x+3}{123}+\frac{x+4}{122}+\frac{x+126}{5}=0\)
\(\frac{x+1}{125}+\frac{x+2}{124}+\frac{x+3}{123}+\frac{x+4}{122}+\frac{x+146}{5}=0\)
\(\left(\frac{x+1}{125}+1\right)+\left(\frac{x+2}{124}+1\right)+\left(\frac{x+3}{123}+1\right)+\left(\frac{x+4}{122}+1\right)+\left(\frac{x+146}{5}-4\right)=0\)
\(\frac{x+126}{125}+\frac{x+126}{124}+\frac{x+126}{123}+\frac{x+126}{122}+\frac{x+126}{5}=0\)
\(\left(x+126\right).\left(\frac{1}{125}+\frac{1}{124}+\frac{1}{123}+\frac{1}{122}+\frac{1}{5}\right)=0\)
vì \(\left(\frac{1}{125}+\frac{1}{124}+\frac{1}{123}+\frac{1}{122}+\frac{1}{5}\right)\ne0\)nên x + 126 = 0 \(\Rightarrow\)x = -126
TÌM X BIẾT: \(|x+\frac{1}{2}|+|x+\frac{1}{6}|+|x+\frac{1}{12}|+|x+\frac{1}{20}|+...+|x+\frac{1}{110}|=11x\)
Giúp mik giải nha các ông tướng.Đây là câu hỏi 1000 năm có 1 ai nhanh mk tick cho.
Ta có : \(\left|x+\frac{1}{2}\right|+\left|x+\frac{1}{6}\right|+\left|x+\frac{1}{12}\right|+...+\left|x+\frac{1}{110}\right|\ge0\forall x\)
=> 11x \(\ge\)0
=> x \(\ge\)0
Khi đó \(\orbr{\begin{cases}x+\frac{1}{2}+x+\frac{1}{6}+x+\frac{1}{12}+...+x+\frac{1}{110}=11x\left(10\text{ số hạng x }\right)\\x+\frac{1}{2}+x+\frac{1}{6}+x+\frac{1}{12}+...+x+\frac{1}{110}=-11x\left(10\text{ số hạng x}\right)\end{cases}}\)
=> \(\orbr{\begin{cases}10x+\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{110}\right)=11x\\10x+\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{110}\right)=-11x\end{cases}}\)
=> \(\orbr{\begin{cases}10x+\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{10.11}\right)=11x\\10x+\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{10.11}\right)=-11x\end{cases}}\)
=> \(\orbr{\begin{cases}10x+\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{10}-\frac{1}{11}\right)=11x\\10x+\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{10}-\frac{1}{11}\right)=-11x\end{cases}}\)
=> \(\orbr{\begin{cases}10x+\left(1-\frac{1}{11}\right)=11x\\10x+\left(1-\frac{1}{11}\right)=-11x\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{10}{11}\\21x=-\frac{10}{11}\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{10}{11}\left(\text{tm}\right)\\x=-\frac{10}{231}\left(\text{loại}\right)\end{cases}}}\)
Vậy \(x=\frac{10}{11}\)
Tìm số hữu tỉ x, biết:
a, \(\frac{x-100}{24}+\frac{x-98}{26}+\frac{x-96}{28}=3\)3
b, \(\frac{x-1}{65}+\frac{x-3}{63}=\frac{x-5}{61}+\frac{x-7}{59}\)
c, \(\frac{x-28-124}{2011}+\frac{x-124-2011}{28}+\frac{x-2011-28}{124}=3\)
giúp với gấp lắm
CHO A=\(24X^2-2X+\frac{999X+1000}{X+1}-\frac{11X^2+4X-8}{X^2-1}+\frac{999X-1000}{X-1}\)
A) RÚT GỌN A
B) TÌM X ĐỂ A=2016
1. So sánh:
a. 1 và \(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+.....+\frac{1}{2^{50}}\)
b. \(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+.....+\frac{1}{3^{100}}\)với \(\frac{1}{2}\)
c. \(\frac{1}{4}+\frac{1}{4^2}+\frac{1}{4^6}+.....\frac{1}{4^{1000}}\)với \(\frac{1}{3}\)
2. Tìm x, biết:
a.\(\left(\frac{2}{5}-x\right):1\frac{1}{3}+\frac{1}{2}=-4\)
b.\(3-\frac{1-\frac{1}{2}}{1+\frac{1}{x}}=2\frac{2}{3}\)
c.\(4^x+4^{x+3}=4160\)
d.\(2^{x-1}+5.2^{x-2}=\frac{7}{32}\)
e.\(\frac{x-100}{24}+\frac{x-98}{26}+\frac{x-96}{24}=3\)
g.\(\frac{x-1}{65}+\frac{x-3}{63}+=\frac{x-5}{61}+\frac{x-7}{59}\)
Tìm x biết
a \(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}...........+\frac{1}{2.\left(x-1\right)}=\frac{999}{1000}\)
b \(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+.........+\frac{1}{2.\left(x+5\right)}=\frac{101}{1540}\)
tìm x biết a)\(\frac{x-100}{24}+\frac{x-98}{26}+\frac{x-96}{28}=3\)
b)\(\frac{x-28-124}{2011}+\frac{x-124-2011}{28}+\frac{x-2011-28}{124}=3\)
a )
\(\Rightarrow\frac{x-100}{24}-1+\frac{x-98}{26}-1+\frac{x-96}{26}-1=0\)
\(\frac{x-124}{24}+\frac{x-124}{26}+\frac{x-124}{28}=0\)
\(\left(x-124\right)\left(\frac{1}{26}+\frac{1}{24}+\frac{1}{28}\right)=0\)
\(\Rightarrow x-124=0\Rightarrow x=124\)
b)
\(\frac{x-28-124}{2011}-1+\frac{x-124-2011}{28}-1+\frac{x-2011-28}{124}-1=0\)
\(\Rightarrow\frac{x-2163}{2011}+\frac{x-2163}{28}+\frac{x-2163}{124}=0\)
\(\left(x-2163\right)\left(\frac{1}{2011}+\frac{1}{28}+\frac{1}{124}\right)=0\)
=) x - 2163 =0
x= 2163