Các câu hỏi tương tự
1,Tính nhanh
a,3x\(\left(\frac{1}{7}+\frac{1}{3}-\frac{3}{14}\right):\frac{11}{14}\)
b,\(\left(\frac{21}{8}+\frac{1}{2}\right):\frac{5}{6}\)
3,Tìm x,biết
a,\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+......+\frac{2}{x\cdot\left(x+1\right)}=\frac{2016}{2018}\)
b,720:\(720:[41-\left(2\cdot x-5\right)]=120\)
Tìm X biết
a) \(x\cdot\frac{2}{7}\cdot\frac{3}{4}=\frac{5}{21}\)
b) \(x\cdot\frac{1}{2}=\frac{1}{3}\)
c) \(x:\frac{4}{5}=\frac{25}{8}:\frac{5}{4}\)
\(A=\frac{1\cdot2}{2\cdot2}\cdot\frac{2\cdot3}{3\cdot3}\cdot\frac{3\cdot4}{4\cdot4}\cdot\frac{4\cdot5}{5\cdot5}\cdot.................\cdot\frac{2012\cdot2013}{2013\cdot2013}\)với
\(B=\frac{2012\cdot2013-2012\cdot2012}{2012\cdot2011+2012\cdot2}\)
tính ( theo mẫu ) :
\(a,\frac{9}{10}\cdot\frac{5}{6}\) \(b,\frac{6}{25}:\frac{21}{20}\)\(c,\frac{40}{7}\cdot\frac{14}{5}\)\(d,\frac{17}{13}:\frac{51}{26}\)
Mẫu : a, \(\frac{9}{10}\cdot\frac{5}{6}=\frac{9\cdot5}{10\cdot6}=\frac{3\cdot3\cdot5}{5\cdot2\cdot3\cdot2}=\)3*3*5 / 5* 2* 3 * 2 = \(\frac{3}{4}\)
Tìm x, biết :
a) \(x\cdot\frac{1}{2}+x\cdot\frac{1}{4}+x\cdot\frac{1}{8}=\frac{21}{24}\)
b) (x+4)+(x+9)+(x+14)+...+(x+44)+(x+49)=1430
c) x* 0,25-0,5=1
a.\(x+x\cdot\frac{1}{3}:\frac{2}{9}+x:\frac{2}{7}=252\)
b.\(\left(3\cdot x-0.8\right):x+14.5=15\)
bài 1: tìm x:
a) \(x\cdot\frac{7}{9}=\frac{2}{3}+2\frac{1}{2}\) b) \(\frac{5}{7}+x:\frac{9}{4}=\frac{4}{3}\)
a)\(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+....+\frac{1}{2017\cdot2018}\) b)\(\left[x\cdot\frac{5}{3}-1\right]:9=3\frac{1}{2}:2,25\)
dấu chấm là dấu nhân nha :3
Tính nhanh:
\(987654321\cdot\frac{1+1\cdot2+2\cdot3+3\cdot4+4\cdot5+5\cdot6+6\cdot7+7\cdot8+8\cdot9+9\cdot...\cdot999+999\cdot1000+1000}{1000+1000\cdot1001+1001\cdot1002+1002\cdot1003+1003\cdot1004+1004\cdot1005+1005\cdot...\cdot9999+9999\cdot10000+10000}\)