=>x(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9)+99/x=-3/7
=>8/9x+99/x=-3/7
\(\Leftrightarrow\dfrac{8x}{9}+\dfrac{99}{x}=\dfrac{-3}{7}\)
\(\Leftrightarrow\dfrac{8x^2+99\cdot9}{9x}=\dfrac{-3}{7}\)
\(\Leftrightarrow-56x^2-6237=27x\)
hay \(x\in\varnothing\)
tìm x
a) \(\dfrac{3}{7}x-\dfrac{2}{3}x=\dfrac{10}{21}\)
b) \(\dfrac{7}{35}:\left(x-\dfrac{1}{3}\right)=-\dfrac{2}{25}\)
a) Tìm x biết: \(\dfrac{x+1}{100}+\dfrac{x+2}{99}=\dfrac{x+3}{98}+\dfrac{x+4}{97}\)
b) So sánh \(\dfrac{3}{1^2.2^2}+\dfrac{5}{2^2.3^2}+\dfrac{7}{3^2.4^2}+...+\dfrac{19}{9^2.10^2}\) với 1
c) Tìm GTNN của: A= |x-10|+|x-5|
2. tìm x
a. \(\dfrac{2}{3}x+1=\dfrac{7}{15}\)
b. \(3^{x+2}-3^x=24\)
c. \(\dfrac{x}{12}=\dfrac{5}{9}\)
d. \(\dfrac{-2}{3}:x+\dfrac{5}{8}=\dfrac{-7}{12}\)
câu 1 . tìm x
a. \(x:3\dfrac{1}{15}=1\dfrac{1}{2}\)
b.\(x.\dfrac{3}{2}=\dfrac{-7}{6}\)
c. \(\dfrac{5}{6}+\dfrac{1}{4}:x=\dfrac{-2}{3}\)
d. \(\dfrac{-2}{13}.x=\dfrac{-9}{26}\)
e. \(\dfrac{1}{2}.x-\dfrac{1}{10}=\dfrac{2}{3}\)
f.\(-52+\dfrac{2}{3}.x=-46\)
Tìm số chưa biết
a)\(\dfrac{x}{y}=\dfrac{9}{7};\dfrac{y}{z}=\dfrac{7}{3};x=y-z=-15\)
b)\(\dfrac{x}{-3}=\dfrac{y}{-8};x^2-y^2=-\dfrac{44}{5}\)
Tìm x biết
a) \(\dfrac{-2}{5}+\dfrac{5}{3}\left(\dfrac{3}{2}-\dfrac{4}{15}x\right)=\dfrac{-7}{6}\)
b) \(\left(\dfrac{1}{4}x-1\right)+\left(\dfrac{2}{3}x-2\right)-\left(\dfrac{5}{8}x+1\right)=5\)
Ai nhanh 3 tick nha
Tìm x :
a) \(\dfrac{2x-3}{3}+\dfrac{-3}{2}=\dfrac{5-3x}{6}-\dfrac{1}{3}\)
b) \(\dfrac{2}{3x}-\dfrac{3}{12}=\dfrac{4}{5}-\left(\dfrac{7}{x}-2\right)\)
c) \(\dfrac{x+2014}{2}+\dfrac{2x+4028}{7}=\dfrac{x+2009}{5}+\dfrac{x+2020}{6}\)
d)\(\dfrac{3}{\left(x+2\right)\left(x+5\right)}+\dfrac{5}{\left(x+5\right)\left(x+10\right)}+\dfrac{7}{\left(x+10\right)\left(x+18\right)}=\dfrac{x}{\left(x+2\right)\left(x+17\right)}\)
Help me , bn nào giải đc bài nò thì giải nha !!! =))
Tìm x biết :
a) \(\dfrac{1}{4}x-1+\dfrac{1}{3}\left(\dfrac{5}{2}x-7\right)-\left(\dfrac{5}{8}x-2\right)=\dfrac{7}{2}\)
b) \(\left|2-\dfrac{3}{2}x\right|-4=x+2\)
c) \(-3\left(\dfrac{2}{5}x-\dfrac{1}{5}\right)-x\left(x-\dfrac{1}{2}\right)=\dfrac{1}{6}-x^2\)
a) \(\left|x+\dfrac{1}{4}\right|-4=-2\)
b) \(-\dfrac{15}{12}x+\dfrac{3}{7}=\dfrac{6}{5}x-\dfrac{1}{2}\)
