\(\dfrac{3}{1\cdot4}+\dfrac{4}{4\cdot8}+\dfrac{5}{8\cdot13}+..........+\dfrac{10}{43\cdot53}\)
\(=1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{8}+\dfrac{1}{8}-\dfrac{1}{13}+....................+\dfrac{1}{43}-\dfrac{1}{53}\)
\(=1-\dfrac{1}{53}\)
\(=\dfrac{52}{53}\)
Bài 1. Tính
A= \(\left(8\dfrac{2}{7}-4\dfrac{2}{7}\right)-3\dfrac{4}{9}\)
B= \(\left(10\dfrac{2}{9}-6\dfrac{2}{9}\right)+2\dfrac{3}{5}\)
Bài 2. Tính
a) \(5\dfrac{1}{2}.3\dfrac{1}{4}\) b) \(6\dfrac{1}{3}:4\dfrac{2}{9}\) c) \(4\dfrac{3}{7}.2\)
Thực hiện các phép tính:
\(a,\left(\dfrac{7}{16}+\dfrac{-1}{8}+\dfrac{9}{32}\right):\dfrac{5}{4}\) \(b,10\dfrac{2}{9}+2\dfrac{3}{5}+6\dfrac{2}{9}\)
\(c,30\%-2\dfrac{2}{5}+0,2.\dfrac{1}{2}\) \(d,\dfrac{-25}{30}.\dfrac{37}{44}+\dfrac{-25}{30}.\dfrac{13}{44}+\dfrac{-25}{30}.\dfrac{-6}{44}\)
Tính giá trị biểu thức: M= \(\left(\dfrac{\dfrac{2}{5}-\dfrac{2}{9}+\dfrac{2}{11}}{\dfrac{7}{5}-\dfrac{7}{9}+\dfrac{7}{11}}-\dfrac{\dfrac{1}{3}-\dfrac{1}{3}+\dfrac{1}{5}}{1\dfrac{1}{6}-\dfrac{7}{8}+\dfrac{7}{10}}\right):\dfrac{2021}{2022}\)
Thực hiện phép tính ( tính hợ lí nếu được)
a, \(\dfrac{3}{4}+\dfrac{9}{5}:\dfrac{3}{2}-1\) b, \(\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{4}{13}.\dfrac{6}{7}\)
Thực hiện phép tính:
a) \(\dfrac{8}{13}\) + \(\dfrac{5}{13}\)
b)\(\dfrac{2}{3}\) + \(\dfrac{-2}{5}\) + \(\dfrac{-5}{6}\) - \(\dfrac{13}{10}\)
c) -\(\dfrac{2}{7}\) - (\(\dfrac{5}{11}\) - \(\dfrac{9}{7}\)) + \(\dfrac{5}{11}\)
d) \(\dfrac{-3}{7}\) x \(\dfrac{-1}{9}\) + \(\dfrac{7}{-18}\) x \(\dfrac{-3}{7}\) + \(\dfrac{5}{6}\) x \(\dfrac{-3}{7}\)
e) \(11\dfrac{1}{4}\) - (\(2\dfrac{5}{7}\) + \(5\dfrac{1}{4}\))
f) (\(8\dfrac{5}{11}\) + \(3\dfrac{5}{8}\)) - \(3\dfrac{5}{11}\)
g) -\(\dfrac{1}{4}\) x \(13\dfrac{9}{11}\) - 0,25 x \(6\dfrac{2}{11}\)
h) \(\dfrac{4}{9}\) : (-\(\dfrac{1}{7}\)) + \(6\dfrac{5}{9}\) : (-\(\dfrac{1}{7}\))
\(\dfrac{3}{4}.\dfrac{7}{9}.\dfrac{1}{9}.\dfrac{7}{4}\)
\(\dfrac{6}{7}.\dfrac{8}{13}-\dfrac{6}{9}.\dfrac{9}{7}+\dfrac{5}{13}.\dfrac{6}{7}\)
2.11.\(\dfrac{3}{4}.\dfrac{9}{121}\)
Bài 1 . Thực hiện phép tính sau :
a. \(\dfrac{-4}{11}\). \(\dfrac{7}{9}\)+\(\dfrac{-4}{11}\) . \(\dfrac{2}{9}\) - \(\dfrac{7}{11}\)
b. \(\dfrac{3}{5}\):\(\dfrac{-7}{10}\)+ 0,5 - \(\left(-\dfrac{9}{14}\right)\)
c. \(\dfrac{3}{5}\)-\(\dfrac{8}{5}\): (5,25+75%)
Bài 2 . Tìm x :
a) x - \(\dfrac{1}{2}\)= \(\dfrac{-1}{10}\) b.\(\dfrac{2}{3}x\) - \(\dfrac{7}{6}\)=\(\dfrac{5}{2}\) c)2,5 - \(\left(\dfrac{1}{8}x+\dfrac{1}{2}\right)\) =\(\dfrac{3}{4}\)
\(\dfrac{-1}{3}.\dfrac{2}{5}\)
\(\dfrac{-3}{7}.\dfrac{4}{15}\)
\(\dfrac{-9}{3}.\dfrac{15}{27}\)
\(\dfrac{-5}{6}.\)( -12 )
\(\dfrac{-12}{4}.\dfrac{8}{9}\)
\(-3.\dfrac{7}{6}\)
\(\dfrac{-15}{9}.\dfrac{27}{5}\)
\(-9.\dfrac{4}{27}\)
8. \(\dfrac{-5}{9}\) + \(\dfrac{8}{15}\) + \(\dfrac{-2}{11}\) + \(\dfrac{4}{-9}\) + \(\dfrac{7}{15}\)
9. \(\dfrac{2}{7}\) + (\(\dfrac{-2}{5}\) + \(\dfrac{5}{7}\))
10. \(\dfrac{7}{19}\). \(\dfrac{8}{11}\) + \(\dfrac{3}{11}\).\(\dfrac{7}{19}\)+\(\dfrac{-12}{19}\)
11. \(\dfrac{-5}{7}\).\(\dfrac{2}{11}\) + \(\dfrac{-5}{7}\).\(\dfrac{9}{11}\)
12. \(\dfrac{-5}{13}\) + \(\dfrac{5}{7}\) + \(\dfrac{20}{41}\) + \(\dfrac{-8}{13}\) + \(\dfrac{21}{41}\)
Giúp tớ với ạ! Tớ cảm ơn! Các cậu chỉ cần ghi đáp án cuối cùng thôi ạ! Cảm ơn các cậu<3
