\(\frac{4}{x}=\frac{1}{5}\)
\(\frac{4}{x}=\frac{4}{20}\)
\(\Rightarrow x=20\)
\(\frac{4}{x}=\frac{1}{5}\Rightarrow4\times5=1\times x\)
=>20=x
=>x=20
4/x=1/5
4*5=x*1
20=x*`1
=>x=20:1
x=20
Vậy x=20
\(\frac{4}{x}=\frac{1}{5}\)
\(\frac{4}{x}=\frac{4}{20}\)
\(\Rightarrow x=20\)
\(\frac{4}{x}=\frac{1}{5}\Rightarrow4\times5=1\times x\)
=>20=x
=>x=20
4/x=1/5
4*5=x*1
20=x*`1
=>x=20:1
x=20
Vậy x=20
\(A=\left(6:\frac{3}{5}-1\frac{1}{6}x\frac{6}{7}\right):\left(4\frac{1}{5}x\frac{10}{11}+5\frac{2}{11}\right)\)\(B=\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{4}\right)x.......x\left(1-\frac{1}{2015}\right)x\left(1-\frac{1}{2016}\right)\)
\(C=5\frac{9}{10}:\frac{3}{2}-\left(2\frac{1}{3}x4\frac{1}{2}-2x2\frac{1}{3}\right):\frac{7}{4}\)
Tính nhanh : \(\frac{1}{2}x\frac{1}{2}+\frac{1}{2}x\frac{1}{3}+\frac{1}{3}x\frac{1}{4}+\frac{1}{4}x\frac{1}{5}+\frac{1}{5}x\frac{1}{6}\)
\(HELP\) \(ME\)\(!\)
1.
\(\frac{3}{4}x\frac{8}{5}:1\frac{1}{6}=\)\(2\frac{1}{3}x1\frac{1}{4}-\frac{7}{5}=\)\(4\frac{2}{3}+1\frac{1}{4}+2\frac{1}{3}+2\frac{3}{7}=\)2.
\(x.\frac{1}{2}=\frac{3}{4}+\frac{1}{5}\)\(x-\frac{1}{5}=\frac{2}{3}.\frac{9}{4}\)\(x.\frac{1}{5}+\frac{2}{3}=\frac{5}{4}\)\(\frac{13}{5}:x-\frac{1}{2}=\frac{4}{5}.\frac{15}{16}\)\(x:\frac{4}{9}+\frac{1}{3}=\frac{2}{5}.1\frac{13}{2}\)Chú ý: Dấu chấm là dấu nhân1/ Tìm x :
\(\frac{x\times2+5}{x+5}=\frac{6}{4}\)
2/ Tính nhanh :
a) \(\frac{4}{1\times5}+\frac{4}{5\times9}+\frac{4}{9\times13}+\frac{4}{13\times17}+\frac{4}{17\times21}\)
b) \(\left(1-\frac{1}{2}\right)\times\left(1-\frac{1}{3}\right)\times\left(1-\frac{1}{4}\right)\times.......\times\left(1-\frac{1}{2017}\right)\)
c) \(A=2000-5-5-5-.......-5\)( có 200 số 5 )
Tìm x trong biểu thức sau
\(\left(3\frac{3}{4}:\frac{1}{4}-2\frac{2}{5}\cdot1\frac{1}{4}\right)-\left(3\frac{1}{2}:2,5-\frac{1}{5}\right)-\frac{1}{5}\cdot x=\frac{51}{5}\)
tìm x:
a) \(x-\frac{5}{7}-\frac{13}{14}=1\) b) \(\frac{3}{5}+x+1\frac{1}{5}=\frac{11}{3}\) c) \(x.\frac{4}{5}:2=\frac{6}{7}\) d) \(\frac{6}{5}:x:\frac{5}{4}=\frac{10}{15}\)
a)\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)x\left(1-\frac{1}{5}\right)x......x\left(1-\frac{1}{18}\right)x\left(1-\frac{1}{19}\right)x\left(1-\frac{1}{20}\right)\)
b)\(1\frac{1}{2}x1\frac{1}{3}x1\frac{1}{4}x1\frac{1}{5}x......x1\frac{1}{2005}x1\frac{1}{2006}x1\frac{1}{2007}\)
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) \(x:\frac{4}{5}=\frac{25}{8}:\frac{5}{4}\)
tinh bằng cách thuật tiện nhất
\(\frac{1}{10}x\frac{2}{9}x\frac{3}{8}x\frac{4}{7}x\frac{5}{6}x\frac{6}{5}x\frac{7}{4}x\frac{8}{3}x\frac{9}{2}\)
Tìm x
a \(\frac{3}{4}+\frac{1}{4}xX=2\)
b X - \(\frac{2}{3}x\frac{9}{4}=2,5-\frac{1}{2}\)
c \(2xX+\frac{1}{3}=\frac{4}{3}\)
d \(X:\frac{2}{3}+0,75=\frac{9}{4}+3\)
e \(\frac{6}{4}:X+\frac{1}{2}=\frac{9}{4}x\frac{2}{3}\)
f \(Xx\frac{3}{5}-\frac{2}{5}=3\frac{3}{4}-1\)