3) \(\dfrac{3}{4}.x-\dfrac{5}{3}.x=\dfrac{7}{12}\)
\(\left(\dfrac{3}{4}-\dfrac{5}{3}\right).x=\dfrac{7}{12}\)
\(-\dfrac{11}{12}.x=\dfrac{7}{12}\)
\(x=\dfrac{7}{12}:\left(-\dfrac{11}{12}\right)\)
\(x=-\dfrac{7}{11}\)
Tính giá trị biểu thức :
\(\dfrac{1}{2}-\left(\dfrac{1}{3}+\dfrac{2}{3}\right)+\left(\dfrac{1}{4}+\dfrac{2}{4}+\dfrac{3}{4}\right)-\left(\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{4}{5}\right)+\left(\dfrac{1}{6}+\dfrac{2}{6}+\dfrac{3}{6}+\dfrac{4}{6}+\dfrac{5}{6}\right)-\left(\dfrac{1}{7}+\dfrac{2}{7}+\dfrac{3}{7}+\dfrac{4}{7}+\dfrac{5}{7}+\dfrac{6}{7}\right)+...+\left(100+...+\dfrac{99}{100}\right)\)
\(\dfrac{-3}{4}x\dfrac{4}{7}+\dfrac{-3}{5}x\dfrac{3}{7}-\dfrac{2}{5}\)
\(\left(\dfrac{3}{4}x\dfrac{5}{6}-\dfrac{7}{12}\right)x\left(\dfrac{-12}{7}\right)\)
\(1,4x\dfrac{15}{19}x\left(\dfrac{4}{5}x\dfrac{-2}{3}\right)+\dfrac{7}{15}\)
Tính nha
BT3: Tìm x, biết:
7) \(\dfrac{-5}{17}+\dfrac{3}{17}\le\dfrac{x}{17}\le\dfrac{13}{17}+\dfrac{-11}{17}\)
8) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)
Tính \(\dfrac{P}{A}\)biết :
P=\(\dfrac{2013}{2}+\dfrac{2013}{3}+\dfrac{2013}{4}+...+\dfrac{2013}{2014}\)
A = \(\dfrac{2013}{1}+\dfrac{2012}{2}+\dfrac{2011}{1}+....+\dfrac{1}{2013}\)
Bài 1 : Tìm x
a) 4\(\dfrac{1}{2}\)x : \(\dfrac{5}{12}\)=0,5 b)1,5+1\(\dfrac{1}{4}\).x= \(\dfrac{2}{3}\) c) 7,5.1\(\dfrac{3}{4}\)=\(6\dfrac{2}{5}\) d)(x - 5):\(\dfrac{1}{3}\)=\(\dfrac{2}{5}\) e) (4,5-2x):\(\dfrac{3}{4}\)=1\(\dfrac{1}{3}\) f) (2,7x - 1\(\dfrac{1}{2}\)x) : \(\dfrac{2}{7}=\dfrac{-21}{7}\)
Bài 2 : tìm a,b biết
\(\dfrac{a}{27}=\dfrac{-5}{9}=\dfrac{-45}{b}\)
a)x=\(\dfrac{1}{4}+\dfrac{2}{13}\)
b)\(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\)
c)\(\dfrac{-8}{3}+\dfrac{-1}{3}\le x\le\dfrac{-2}{7}+\dfrac{-5}{7}\)
d)\(\dfrac{-5}{6}+\dfrac{8}{3}\dfrac{29}{-x}\le x\le\dfrac{-1}{2}+2+\dfrac{5}{2}\)
1. Tim x:
a. \(\dfrac{x}{5}\) = \(\dfrac{5}{6}\) + \(\dfrac{-19}{30}\)
b. \(\dfrac{-5}{6}\) \(-x\) = \(\dfrac{7}{12}\)\(-\) \(\dfrac{1}{3}\)\(\times\) \(x\)
c.2016\(^{^{ }3}\) \(\times\)2016\(^{^{ }x}\) = 2016\(^{^{ }8}\)
d. \((x+\dfrac{3}{4}):\dfrac{5}{2}=3^1_2\)
e. (2,8 \(x\) \(-\) 2\(^5\)) : \(\dfrac{2}{3}=3^2\)
f. \(\dfrac{4}{7}\times x-\dfrac{2}{3}=\dfrac{2}{5}\)
g. \((\dfrac{3x}{7}+1):\left(-4\right)=\dfrac{-1}{28}\)
2. Thuc hien phep tinh:
a. \(\dfrac{1}{2}+\dfrac{1}{2}\times\dfrac{2}{3}-\dfrac{1}{3}:\dfrac{3}{4}+1^4_5\)
b. \(\dfrac{7\times5^2-7^2}{7\times24+21}\)
c. \(\dfrac{2}{3}+\dfrac{1}{3}\times(-\dfrac{4}{9}+\dfrac{5}{6}):\dfrac{7}{12}\)
bài 1 : tính
a,\(\dfrac{-6}{11}\): (\(\dfrac{3}{5}.\)\(\dfrac{4}{11}\))
b, \(\dfrac{7}{12}\) + \(\dfrac{5}{12}\) : 6 - \(\dfrac{11}{36}\)
c, ( \(\dfrac{4}{5}\) +\(\dfrac{1}{2}\) ) : ( \(\dfrac{3}{13}\)-\(\dfrac{8}{13}\))
d, ( \(\dfrac{2}{3}\) -\(\dfrac{1}{4}\) +\(\dfrac{5}{11}\) ) : ( \(\dfrac{8}{12}\) +1 - \(\dfrac{7}{11}\) )
bài 2 , tìm x, biết
a, \(\dfrac{-2}{5}\). x +\(\dfrac{4}{3}\) = \(\dfrac{7}{3}\)
b,\(\dfrac{9}{8}\)+\(\dfrac{3}{8}\)-x = 0,125
c,\(\dfrac{3}{4}\): x =\(\dfrac{-7}{12}\)
d,\(\dfrac{3}{8}\)-\(\dfrac{1}{6}\)- x = \(\dfrac{1}{4}\)
e, \(\dfrac{1}{3}\)+\(\dfrac{1}{2}\): x = -4
bài 1: tìm x bt:
a\(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)
b, \(5\dfrac{4}{7}:x=13\)
c, (2 và 4/5.x-50) :2/3= 51
d,\(\left(x+\dfrac{1}{2}\right).\left(\dfrac{2}{3}-2x\right)=0\)
e, \(\dfrac{2}{3}-\dfrac{1}{2}x=\dfrac{5}{12}\)
giúp mk nhs!!!!!!!!!!