\(a.\left(\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+.......+\dfrac{1}{9.10}\right).100-\left[\dfrac{5}{2}:\left(x+\dfrac{206}{100}\right)\right]:\dfrac{1}{2}=89\)
Tìm x:
a)\(2016x+\left(\dfrac{7}{12}+\dfrac{4}{21}+\dfrac{2}{24}+\dfrac{11}{30}+\dfrac{3}{40}+\dfrac{15}{56}\right)-\left(\dfrac{2}{3}+\dfrac{2}{4}+\dfrac{2}{5}\right)=0\)
b\(\dfrac{2x-1}{x+2015}-\dfrac{4025}{x+2017}=\dfrac{x-2014}{2x-4036}-\dfrac{x-2013}{2x-4030}\) (x thuộc N)
c)\(\left(1+\dfrac{1}{1.3}\right)\left(1+\dfrac{1}{2.4}\right)\left(1+\dfrac{1}{3.5}\right)...\left(1+\dfrac{1}{x\left(x+2\right)}\right)=\dfrac{4016}{2007}\)
AI GIÚP MK VỚI MK TICK CHO
tìm x biết
a) \(\dfrac{2x-3}{3}+-\dfrac{3}{2}=\dfrac{5-2x}{6}-\dfrac{1}{2}\)
b) \(\left(3x-\dfrac{1}{2}\right).\left(3-\dfrac{1}{2}x\right).\left(1+\dfrac{3}{4}:x\right)=0\)
c) \(\left(3-\dfrac{9}{10}-|x+2|\right):\left(\dfrac{19}{20}-1-\dfrac{2}{3}\right)+\dfrac{4}{5}=1\)
Bài 1 : Tìm x , biết :
a, \(\dfrac{-3}{x}=\dfrac{x}{-27}\) b, \(\dfrac{2}{3}\)của x là ( -150 ) c,\(\dfrac{2}{2.4}+\dfrac{2}{4.6}+...+\dfrac{2}{x.\left(x+2\right)}=\dfrac{4}{9}\)
Bài 2 : Tính :
A = \(\left(\dfrac{1}{99}+\dfrac{12}{999}+\dfrac{123}{999}\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{6}\right)\)
Bài 1: Tìm x, biết:
a, \(\left(x+\dfrac{1}{4}-\dfrac{1}{3}\right):\left(2+\dfrac{1}{6}-\dfrac{1}{4}\right)=\dfrac{7}{46}\)
b, \(\dfrac{13}{15}-\left(\dfrac{13}{21}+x\right).\dfrac{7}{12}=\dfrac{7}{10}\)
Bài 2: Thực hiện phép tính:
a, \(\left(2\dfrac{5}{6}+1\dfrac{4}{9}\right):\left(10\dfrac{1}{12}-9\dfrac{1}{2}\right)\)
b, 1\(\dfrac{5}{18}-\dfrac{5}{18}.\left(\dfrac{1}{15}+1\dfrac{1}{12}\right)\)
c, \(-\dfrac{1}{7}.\left(9\dfrac{1}{2}-8,75\right):\dfrac{2}{7}+0,625:1\dfrac{2}{3}\)
Tìm x, biết :
a) \(\left(\dfrac{31}{20}-\dfrac{26}{45}\right).\dfrac{-36}{35}< x< \left(\dfrac{51}{56}+\dfrac{8}{21}+\dfrac{1}{3}\right).\dfrac{8}{13}\)
b) \(\dfrac{-3}{5}.x=\dfrac{1}{4}+0,75\)
c) \(\left(\dfrac{1}{7}-\dfrac{1}{3}\right).x=\dfrac{28}{3}.\left(\dfrac{1}{4}-\dfrac{1}{7}\right)\)
d) \(\dfrac{5}{7}.x=\dfrac{9}{8}-0,125\)
e)\(\left(\dfrac{2}{11}+\dfrac{1}{3}\right).x=\left(\dfrac{1}{7}-\dfrac{1}{8}\right).56\)
Tìm x:
a) \(\dfrac{1}{5.8}+\dfrac{1}{8.11}+\dfrac{1}{11.14}+...+\dfrac{1}{x.\left(x+3\right)}=\dfrac{101}{1540}\)
b) \(1+\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{10}+...+\dfrac{1}{x.\left(x+1\right):2}=1\dfrac{1991}{1993}\)
Tìm số x , biết
a) \(\dfrac{2}{3}x-\dfrac{3}{2}x=\dfrac{5}{12}\)
b) \(\dfrac{2}{5}+\dfrac{3}{5}.\left(3x-3,7\right)=-\dfrac{53}{10}\)
c) \(\dfrac{7}{9}:\left(2+\dfrac{3}{4}x\right)+\dfrac{5}{9}=\dfrac{23}{27}\)
d) \(\dfrac{-2}{3}.x+\dfrac{1}{5}=\dfrac{3}{10}\)
e) \(\left|x\right|-\dfrac{3}{4}=\dfrac{5}{3}\)
f) \(\left|2x-\dfrac{1}{3}\right|+\dfrac{5}{6}=1\)
a, \(\dfrac{5}{2}-3\left(\dfrac{1}{3}-x\right)=\dfrac{1}{4}-7x\)
b,\(60\%.x+\dfrac{2}{3}.x=\dfrac{1}{3}.6\dfrac{1}{3}\)
c, \(\left(\dfrac{9}{2}.x-2x\right).\left(-1\dfrac{4}{7}\right)=\dfrac{11}{4}\)
d,\(\left(x+\dfrac{5}{6}\right).2\dfrac{2}{5}-1\dfrac{1}{4}=35\%\)