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a) \(\frac{17}{9}-\frac{17}{9}:\left(\frac{7}{3}+\frac{1}{2}\right)\)
= \(\frac{17}{9}-\frac{17}{9}:\frac{17}{6}\)
= \(\frac{17}{9}-\frac{2}{3}\)
= \(\frac{11}{9}\)
b) \(\frac{4}{3}.\frac{2}{5}-\frac{3}{4}.\frac{2}{5}\)
= \(\frac{2}{5}.\left(\frac{4}{3}-\frac{3}{4}\right)\)
= \(\frac{2}{5}.\frac{7}{12}\)
= \(\frac{7}{30}\)
Mình lười làm quá, hay mình nói kết quả cho bn thôi nha
c) -6
d) 3
e) 3
g) 12
h) \(\frac{23}{18}\)
i) \(\frac{-69}{20}\)
k) \(\frac{-1}{2}\)
l) \(\frac{49}{5}\)
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chắc h có mấy thành cay r nên ko làm bn lên mạng tải phẩn mêm có cánh iair đó :D
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8)\(\frac{4}{9}:\left(-\frac{1}{7}\right)+6\frac{5}{9}:\left(-\frac{1}{7}\right)\)
=\(\frac{4}{9}:\left(-\frac{1}{7}\right)+\frac{59}{9}:\left(-\frac{1}{7}\right)\)
=\(\left(\frac{4}{9}+\frac{59}{9}\right).\left(-7\right)\)
=7.(-7)
=-49
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a) \(\frac{3}{4}+\left(-\frac{1}{8}\right)\)
\(=\frac{6}{8}-\frac{1}{8}=\frac{5}{8}\)
b) \(-\frac{5}{12}+\left(-\frac{7}{24}\right)=\left(-\frac{10}{24}\right)+\left(-\frac{7}{24}\right)=-\frac{17}{24}\)
c) \(1+\left(-\frac{7}{8}\right)=\frac{8}{8}-\frac{7}{8}=\frac{1}{8}\)
d) \(\frac{13}{30}-\frac{1}{3}=\frac{13}{30}-\frac{10}{30}=\frac{3}{30}\)
e) \(\frac{4}{21}-\left(-\frac{5}{28}\right)=\frac{4}{21}+\frac{5}{28}=\frac{16}{84}+\frac{15}{84}=\frac{31}{84}\)
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b) \(\frac{\frac{2}{3}+\frac{5}{7}+\frac{4}{21}}{\frac{5}{6}+\frac{11}{7}-\frac{7}{21}}\)
\(=\frac{\frac{29}{21}+\frac{4}{21}}{\frac{101}{42}-\frac{7}{21}}\)
\(=\frac{\frac{11}{7}}{\frac{29}{14}}\)
\(=\frac{22}{29}.\)
Chúc bạn học tốt!
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a) \(\frac{-3}{5}.y=\frac{21}{10}\)
\(y=\frac{21}{10}:\frac{-3}{5}\)
\(y=\frac{-7}{2}\)
vậy \(y=\frac{-7}{2}\)
b) \(y:\frac{3}{8}=-1\frac{31}{33}\)
\(y:\frac{3}{8}=\frac{-64}{33}\)
\(y=\frac{-64}{33}.\frac{3}{8}\)
\(y=\frac{-8}{11}\)
vậy \(y=\frac{-8}{11}\)
c) \(1\frac{2}{5}.y+\frac{3}{7}=\frac{-4}{5}\)
\(\frac{7}{5}.y+\frac{3}{7}=\frac{-4}{5}\)
\(\frac{7}{5}.y=\frac{-4}{5}-\frac{3}{7}\)
\(\frac{7}{5}.y=\frac{-43}{35}\)
\(y=\frac{-43}{35}:\frac{7}{5}\)
\(y=\frac{-43}{49}\)
vậy \(y=\frac{-43}{49}\)
d) \(\frac{-11}{12}.y+0,25=\frac{5}{6}\)
\(\frac{-11}{12}.y=\frac{5}{6}-0,25\)
\(\frac{-11}{12}.y=\frac{7}{12}\)
\(y=\frac{7}{12}:\frac{-11}{12}\)
\(y=\frac{-7}{11}\)
vậy \(y=\frac{-7}{11}\)
Ta có:
`1 + 4 = 5 = 1 + 1 xx 4`
`2+5 = 12 = 2 + 2 xx 5`
`3+6=21 = 3 + 3 xx 6`
....
`8+11 = 8 + 8 xx 11 = 96`
Phân tích quy luật:
1 + 4 = 5 (5 = 1 x (1 + 4))
2 + 5 = 12 (12 = 2 x (2 + 5))
3 + 6 = 21 (21 = 3 x (3 + 6))
8+11=?
Theo quy luật, ta có: ? = 8 x (8 + 11) = 8 x 19 = 152
Vậy, 8 + 11 = 152