\(\dfrac{x+1}{124}\)+\(\dfrac{x+2}{123}\)=\(\dfrac{x+3}{122}\)+\(\dfrac{x+4}{121}\)
Những câu hỏi liên quan
Chứng minh rằng:\(1-\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{121}-\dfrac{1}{122}+\dfrac{1}{123}=\dfrac{1}{62}+\dfrac{1}{63}+...+\dfrac{1}{122}+\dfrac{1}{123}\)
20 tháng 2 2023 lúc 22:00
Bài 5:
a) \(\dfrac{x+1}{99}+\dfrac{x+4}{96}+\dfrac{x+8}{92}+\dfrac{x+3}{97}+4=0\)
b) \(\dfrac{x-11}{111}+\dfrac{x-12}{112}=\dfrac{x-23}{123}+\dfrac{x-24}{124}\)
\(\Leftrightarrow\left(\dfrac{x-11}{111}+1\right)+\left(\dfrac{x-12}{112}+1\right)=\left(\dfrac{x-23}{123}+1\right)+\left(\dfrac{x-24}{124}+1\right)\)
=>x+100=0
=>x=-100
Đúng 0
Bình luận (0)
a: =>\(\left(\dfrac{x+1}{99}+1\right)+\left(\dfrac{x+4}{96}+1\right)+\left(\dfrac{x+8}{92}+1\right)+\left(\dfrac{x+3}{97}+1\right)=0\)
=>x+100=0
=>x=-100
b: =>(x-11/111+1)+(x-12/112+1)=(x-23/123+1)+(x-24/124+1)
=>x+100=0
=>x=-100
Đúng 0
Bình luận (0)
giải các phương trình sau:
1) \(\dfrac{x-11}{111}+\dfrac{x-12}{112}=\dfrac{x-23}{123}+\dfrac{x-24}{124}\)
2) \(\dfrac{x-5}{1990}+\dfrac{x-15}{1980}=\dfrac{x-1980}{15}+\dfrac{x-1990}{5}\)
3) \(\dfrac{109-x}{91}+\dfrac{107-x}{93}+\dfrac{105-x}{95}+\dfrac{103-x}{97}=-4\)
A-dfrac{68}{123}x-dfrac{23}{79}
B-dfrac{14}{79}x-dfrac{68}{7}x-dfrac{46}{123}
C-dfrac{4}{19}x-dfrac{3}{19}x-dfrac{2}{19} ... dfrac{2}{19}xdfrac{3}{19}xdfrac{4}{19}
a)So sánh A,B,C
b)Tính B:A
Đọc tiếp
A=\(-\dfrac{68}{123}\)x\(-\dfrac{23}{79}\)
B=\(-\dfrac{14}{79}\)x\(-\dfrac{68}{7}\)x\(-\dfrac{46}{123}\)
C=\(-\dfrac{4}{19}\)x\(-\dfrac{3}{19}\)x\(-\dfrac{2}{19}\) ... \(\dfrac{2}{19}\)x\(\dfrac{3}{19}\)x\(\dfrac{4}{19}\)
a)So sánh A,B,C
b)Tính B:A
a) Ta có:
\(A=\dfrac{-68}{123}\cdot\dfrac{-23}{79}=\dfrac{68}{123}\cdot\dfrac{23}{79}\)
\(B=\dfrac{-14}{79}\cdot\dfrac{-68}{7}\cdot\dfrac{-46}{123}=-\left(\dfrac{14}{79}\cdot\dfrac{68}{7}\cdot\dfrac{46}{123}\right)\)
\(C=\dfrac{-4}{19}\cdot\dfrac{-3}{19}\cdot...\cdot\dfrac{0}{19}\cdot...\cdot\dfrac{3}{19}\cdot\dfrac{4}{19}=0\)
Suy ra A là số hữu tỉ dương, B là số hữu tỉ âm và C là 0.
Vậy A > C > B.
b) Ta có:
\(\dfrac{B}{A}=\dfrac{-\left(\dfrac{14}{79}\cdot\dfrac{68}{7}\cdot\dfrac{46}{123}\right)}{\dfrac{68}{123}\cdot\dfrac{23}{79}}=-\dfrac{14}{79}\cdot\dfrac{68}{7}\cdot\dfrac{46}{123}\cdot\dfrac{123}{68}\cdot\dfrac{79}{23}\)
\(\dfrac{B}{A}=-\dfrac{14\cdot68\cdot46\cdot123\cdot79}{79\cdot7\cdot123\cdot68\cdot23}=-\left(2\cdot2\right)=-4\)
Vậy B : A = -4
Đúng 1
Bình luận (0)
13 tháng 10 2021 lúc 18:28
a, (\(\dfrac{1}{2}x-\dfrac{1}{3}\))2 - \(\dfrac{4}{25}=0\) b , (\(1-\dfrac{1}{4}x\) )-\(\dfrac{121}{49}=0\)
a) \(\Rightarrow\left(\dfrac{1}{2}x-\dfrac{1}{3}\right)^2=\dfrac{4}{25}\)
\(\Rightarrow\left[{}\begin{matrix}\dfrac{1}{2}x-\dfrac{1}{3}=\dfrac{2}{5}\\\dfrac{1}{2}x-\dfrac{1}{3}=-\dfrac{2}{5}\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{22}{15}\\x=-\dfrac{2}{15}\end{matrix}\right.\)
b) \(\Rightarrow\left(1-\dfrac{1}{4}x\right)^2=\dfrac{121}{49}\)
\(\Rightarrow\left[{}\begin{matrix}1-\dfrac{1}{4}x=\dfrac{11}{7}\\1-\dfrac{1}{4}x=-\dfrac{11}{7}\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{16}{7}\\x=\dfrac{72}{7}\end{matrix}\right.\)
Đúng 0
Bình luận (0)
\(\left\{1\dfrac{3}{4}-\dfrac{4}{6}\right\}:\left\{1\dfrac{1}{5}+2\dfrac{2}{5}+\dfrac{1}{5}\right\}< x< 1\dfrac{1}{5}.1\dfrac{3}{4}+3\dfrac{2}{11}:2\dfrac{3}{121}\) với x là số tự nhiên
\(\left(1\dfrac{3}{4}-\dfrac{4}{6}\right):\left(1\dfrac{1}{5}+2\dfrac{2}{5}+\dfrac{1}{5}\right)< x< 1\dfrac{1}{5}.1\dfrac{1}{4}+3\dfrac{2}{11}:2\dfrac{3}{121}\)
\(\Leftrightarrow\left(\dfrac{7}{4}-\dfrac{4}{6}\right):\left(\dfrac{6}{5}+\dfrac{12}{5}+\dfrac{1}{5}\right)< x< \dfrac{6}{5}.\dfrac{5}{4}+\dfrac{35}{11}:\dfrac{245}{121}\) \(\Leftrightarrow\left(\dfrac{21}{12}-\dfrac{8}{12}\right):\dfrac{19}{5}< x< \dfrac{3}{2}+\dfrac{35}{11}.\dfrac{121}{245}\) \(\Leftrightarrow\dfrac{13}{12}.\dfrac{5}{19}< x< \dfrac{3}{2}+\dfrac{2}{7}\) \(\Leftrightarrow\dfrac{65}{228}< x< \dfrac{21}{14}+\dfrac{4}{14}\) \(\Leftrightarrow\dfrac{65}{228}< x< \dfrac{25}{14}\) \(\Leftrightarrow x=1\)
Đúng 0
Bình luận (0)
Tìm x,y biết:
1) \(\dfrac{x}{5}=\dfrac{y}{7}\) và x+y = 48
2) \(\dfrac{x}{4}=\dfrac{y}{-7}\) và x-y=33
3) \(\dfrac{x}{y}=-\dfrac{2}{5}\) và x+y =12
4) \(\dfrac{x}{3}=\dfrac{y}{5}\) và 2x+4y=28
5) \(\dfrac{x}{y}=\dfrac{3}{16}\) và 3x-y=35
1) Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\dfrac{x}{5}=\dfrac{y}{7}=\dfrac{x+y}{5+7}=\dfrac{48}{12}=4\)
\(\dfrac{x}{5}=4\Rightarrow x=20\\ \dfrac{y}{7}=4\Rightarrow y=28\)
2) Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\dfrac{x}{4}=\dfrac{y}{-7}=\dfrac{x-y}{4+7}=\dfrac{33}{11}=3\)
\(\dfrac{x}{4}=3\Rightarrow x=12\\ \dfrac{y}{-7}=3\Rightarrow y=-21\)
Đúng 1
Bình luận (0)
Bài 15:a)dfrac{-2}{5}+dfrac{4}{5} . x dfrac{3}{5}b)dfrac{-3}{7} - dfrac{4}{7}:x -2Bài 16a) x - dfrac{10}{3} dfrac{7}{15} . dfrac{3}{5}b) x + dfrac{3}{22} dfrac{27}{121} . dfrac{11}{9}c) dfrac{8}{23} . dfrac{48}{24} - x dfrac{1}{3}d) 1 - x dfrac{49}{65}.dfrac{5}{7}Bài 17: tìm xa) dfrac{62}{7} . x dfrac{29}{9}: dfrac{3}{56}b) dfrac{1}{5} : xdfrac{1}{5}+dfrac{1}{7}bài 18:a)dfrac{2}{5}+dfrac{3}{4}: x dfrac{-1}{2}b)dfrac{5}{7} - dfrac{2}{3} . x dfrac{4}{5}c) dfrac{1}{2}x + dfrac{3}{5}x dfrac{-...
Đọc tiếp
Bài 15:
a)\(\dfrac{-2}{5}\)+\(\dfrac{4}{5}\) . x =\(\dfrac{3}{5}\)
b)\(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\):x = -2
Bài 16
a) x - \(\dfrac{10}{3}\) = \(\dfrac{7}{15}\) . \(\dfrac{3}{5}\)
b) x + \(\dfrac{3}{22}\)= \(\dfrac{27}{121}\) . \(\dfrac{11}{9}\)
c) \(\dfrac{8}{23}\) . \(\dfrac{48}{24}\) - x = \(\dfrac{1}{3}\)
d) 1 - x = \(\dfrac{49}{65}\).\(\dfrac{5}{7}\)
Bài 17: tìm x
a) \(\dfrac{62}{7}\) . x = \(\dfrac{29}{9}\): \(\dfrac{3}{56}\)
b) \(\dfrac{1}{5}\) : x=\(\dfrac{1}{5}\)+\(\dfrac{1}{7}\)
bài 18:
a)\(\dfrac{2}{5}\)+\(\dfrac{3}{4}\): x =\(\dfrac{-1}{2}\)
b)\(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)
c) \(\dfrac{1}{2}\)x + \(\dfrac{3}{5}\)x = \(\dfrac{-2}{3}\)
d) \(\dfrac{4}{7}\).x-x = \(\dfrac{-9}{14}\)
bài 19: tính
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+\(\dfrac{1}{3.4}\)+...+ \(\dfrac{1}{2018.2019}\)
bài 20:tìm x
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+...+\(\dfrac{1}{x.\left(x+1\right)}\)=\(\dfrac{2008}{2009}\)
bài 21: tìm x
\(\dfrac{x+1}{99}\)+\(\dfrac{x+2}{98}\)\(\dfrac{x+3}{97}\)\(\dfrac{x+4}{96}\)=-4
bài 22 : so sánh các phân số sau:
a) \(\dfrac{-1}{5}\)+\(\dfrac{4}{-5}\)và 1
b) \(\dfrac{3}{5}\) và \(\dfrac{2}{3}\)+\(\dfrac{-1}{5}\)
c)\(\dfrac{3}{2}\)+\(\dfrac{-4}{3}\) và \(\dfrac{1}{10}\)+\(\dfrac{-4}{5}\)
d) \(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\) và 2
tim xdfrac{5}{6}x-dfrac{3}{4}dfrac{-1}{4}+dfrac{2}{3}65x−434−1+32-1dfrac{1}{2}-dfrac{2}{3}xdfrac{5}{6}-left(dfrac{-2}{5}right)−121−32x65−(5−2)left(dfrac{4}{5}:x+1,5right):dfrac{2}{3}-1,5(54:x+1,5):32−1,5dfrac{4}{3}x-dfrac{2}{3}dfrac{1}{4}-x34x−3241−xgiup minh nhe minh dang can gap
Đọc tiếp
tim x
\dfrac{5}{6}x-\dfrac{3}{4}=\dfrac{-1}{4}+\dfrac{2}{3}65x−43=4−1+32
-1\dfrac{1}{2}-\dfrac{2}{3}x=\dfrac{5}{6}-\left(\dfrac{-2}{5}\right)−121−32x=65−(5−2)
\left(\dfrac{4}{5}:x+1,5\right):\dfrac{2}{3}=-1,5(54:x+1,5):32=−1,5
\dfrac{4}{3}x-\dfrac{2}{3}=\dfrac{1}{4}-x34x−32=41−x
giup minh nhe minh dang can gap