bài 1 : tính phân số:
a) \(\frac{5}{7}+\frac{4}{9}=?;\frac{4}{5}-\frac{2}{3}=?;\frac{9}{11}+\frac{3}{8}=?;\frac{16}{25}-\frac{2}{5}=?\)=?
b)\(5+\frac{3}{5}=?;10-\frac{9}{16}=?;\frac{2}{3}-\left(\frac{1}{6}+\frac{1}{8}\right)=?\)
c)\(\frac{5}{7}+\frac{7}{6}=?;\frac{7}{12}+\frac{17}{18}=?;\frac{9}{8}+\frac{15}{32}=?;4+\frac{35}{45}=?\)
d)\(\frac{11}{4}-\frac{15}{16}=?;\frac{5}{6}-\frac{5}{8}=?;\frac{196}{64}-2=?;3-\frac{13}{9}=?\)
e)\(\frac{8}{5}+\frac{7}{6}+\frac{5}{9}-2=?;3-\frac{5}{6}-\frac{4}{9}+\frac{32}{24}=?\)
a)Tính bằng cách thuận tiện nhất :
\(\frac{1}{2}x\frac{1}{3}+\frac{1}{3}x\frac{1}{4}+\frac{1}{4}x\frac{1}{5}+\frac{1}{5}x\frac{1}{6}\)
b) Tính :
\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)\)
\(3\frac{1}{5}+4\frac{1}{3}=\left(3+....\right)+\left(\frac{1}{5}+\frac{1}{3}\right)=7+\frac{...}{15}=7\frac{ }{15}\)
A =\(\frac{\left[3+\frac{1}{4}\right]-\frac{2}{5}}{\left[5-\frac{1}{6}\right]+\frac{7}{10}}\)
Tìm x:
a) (2,8x - 32) :\(\frac{2}{3}\)=90
b) 4,5 - 2x . \(1\frac{4}{7}\)=\(\frac{11}{14}\)
c) (x+ \(\frac{1}{4}-\frac{1}{3}\) ): (2+\(\frac{1}{6}-\frac{1}{4}\))=\(\frac{7}{46}\)
d)\(\frac{13}{15}-\left(\frac{13}{21}+x\right).\frac{7}{12}=\frac{7}{10}\)
1 . rút gọn rồi tính
a)\(\frac{16}{24}-\frac{1}{3}=\)
b)\(\frac{4}{5}-\frac{12}{60}=\)
3 . tính rồi rút gọn
a)\(\frac{17}{6}-\frac{2}{6}=\)
b)\(\frac{16}{15}-\frac{11}{15}\)
c)\(\frac{19}{12}-\frac{13}{12}=\)
tính bằng hai cách
a) \(\left(\frac{6}{11}+\frac{5}{11}\right)x\frac{3}{7}\) b) \(\frac{3}{5}x\frac{7}{9}+\frac{3}{5}x\frac{2}{9}\)
c) \(\left(\frac{6}{7}-\frac{4}{7}\right):\frac{2}{5}\) d) \(\frac{8}{15}:\frac{2}{11}+\frac{7}{15}:\frac{2}{11}\)
giúp mik nha
Bài 1:Tính nhanh:
a,\(\frac{2}{3}+\frac{4}{6}+\frac{6}{3}\)
b,\(\frac{3}{4}+\frac{6}{8}+\frac{18}{12}\)
Bài 2:Tính:
a,\(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}\)
b,\(\frac{1}{2}+\frac{1}{3}+\frac{1}{5}+\frac{1}{7}\)
Tính
\(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{2004\times2005}+\frac{1}{2005\times2006}=A\)
\(\frac{1}{6}+\frac{2}{15}+\frac{4}{45}+\frac{2}{99}+\frac{10}{600}=A\)