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Bài 1:
a) Ta có: \(6\frac{5}{7}-\left(1\frac{3}{4}+2\frac{5}{7}\right)\)
\(=6\frac{5}{7}-1\frac{3}{4}-2\frac{5}{7}\)
\(=4\frac{5}{7}-1\frac{3}{4}\)
\(=\frac{33}{7}-\frac{7}{4}\)
\(=\frac{132}{28}-\frac{49}{28}=\frac{83}{28}\)
b) Ta có: \(7\frac{5}{9}-\left(2\frac{3}{4}+3\frac{5}{9}\right)\)
\(=7\frac{5}{9}-2\frac{3}{4}-3\frac{5}{9}\)
\(=4\frac{5}{9}-2\frac{3}{4}\)
\(=\frac{41}{9}-\frac{11}{4}\)
\(=\frac{164}{36}-\frac{99}{36}=\frac{65}{36}\)
c) Ta có: \(\frac{-3}{5}\cdot\frac{5}{7}+\frac{-3}{5}\cdot\frac{3}{7}+\frac{-3}{5}\cdot\frac{6}{7}\)
\(=\frac{-3}{5}\cdot\left(\frac{5}{7}+\frac{3}{7}+\frac{6}{7}\right)\)
\(=\frac{-3}{5}\cdot2=-\frac{6}{5}\)
d) Ta có: \(\frac{1}{3}\cdot\frac{4}{5}+\frac{1}{3}\cdot\frac{6}{5}-\frac{4}{3}\)
\(=\frac{1}{3}\cdot\frac{4}{5}+\frac{1}{3}\cdot\frac{6}{5}-\frac{1}{3}\cdot4\)
\(=\frac{1}{3}\left(\frac{4}{5}+\frac{6}{5}-4\right)\)
\(=\frac{1}{3}\cdot\left(-2\right)=\frac{-2}{3}\)
g) \(6\frac{4}{5}-\left(1\frac{2}{3}+3\frac{4}{5}\right)\)
\(=6\frac{4}{5}-1\frac{2}{3}-3\frac{4}{5}\)
\(=\left(6\frac{4}{5}-3\frac{4}{5}\right)-1\frac{2}{3}\)
\(=\left(6+\frac{4}{5}-3-\frac{4}{5}\right)-1\frac{2}{3}\)
\(=3-\frac{5}{3}=\frac{9}{3}-\frac{5}{3}=\frac{4}{3}\)
h) \(7\frac{5}{9}-\left(2\frac{3}{4}+3\frac{5}{9}\right)\)
\(=7\frac{5}{9}-2\frac{3}{4}-3\frac{5}{9}\)
\(=\left(7\frac{5}{9}-3\frac{5}{9}\right)-2\frac{3}{4}\)
\(=\left(7+\frac{5}{9}-3-\frac{5}{9}\right)-2\frac{3}{4}\)
\(=4-\frac{11}{4}=\frac{16}{4}-\frac{11}{4}=\frac{5}{4}\)
i) \(6\frac{5}{7}-\left(1\frac{3}{4}+2\frac{5}{7}\right)\)
\(=6\frac{5}{7}-1\frac{3}{4}-2\frac{5}{7}\)
\(=\left(6\frac{5}{7}-2\frac{5}{7}\right)-1\frac{3}{4}\)
\(=\left(6+\frac{5}{7}-2-\frac{5}{7}\right)-\frac{7}{4}\)
\(=4-\frac{7}{4}=\frac{16}{4}-\frac{7}{4}=\frac{9}{4}\)
k) \(7\frac{5}{11}-\left(2\frac{3}{7}+3\frac{5}{11}\right)\)
\(=7\frac{5}{11}-2\frac{3}{7}-3\frac{5}{11}\)
\(=\left(7\frac{5}{11}-3\frac{5}{11}\right)-2\frac{3}{7}\)
\(=4-\frac{17}{7}=\frac{28}{7}-\frac{17}{7}=\frac{11}{7}\)
g) Ta có: \(6\frac{4}{5}-\left(1\frac{2}{3}+3\frac{4}{5}\right)\)
\(=\frac{34}{5}-\left(\frac{5}{3}+\frac{19}{5}\right)\)
\(=\frac{34}{5}-\frac{5}{3}-\frac{19}{5}\)
\(=3-\frac{5}{3}=\frac{9}{3}-\frac{5}{3}=\frac{4}{3}\)
h) Ta có: \(7\frac{5}{9}-\left(2\frac{3}{4}+3\frac{5}{9}\right)\)
\(=\frac{68}{9}-\frac{11}{4}-\frac{32}{9}\)
\(=4-\frac{11}{4}=\frac{16}{4}-\frac{11}{4}=\frac{5}{4}\)
i) Ta có: \(6\frac{5}{7}-\left(1\frac{3}{4}+2\frac{5}{7}\right)\)
\(=6+\frac{5}{7}-1-\frac{3}{4}-2-\frac{5}{7}\)
\(=3-\frac{3}{4}=\frac{9}{4}\)
k) Ta có: \(7\frac{5}{11}-\left(2\frac{3}{7}+3\frac{5}{11}\right)\)
\(=7+\frac{5}{11}-2-\frac{3}{7}-3-\frac{5}{11}\)
\(=2-\frac{3}{7}=\frac{11}{7}\)
a)\(\frac{11^4.6-11^5}{11^4-11^5}:\frac{9^8.3-9^9}{9^8.5+9^8.7}\)
\(=1.6:\frac{9^8.3-9^8.9}{9^8.\left(5+7\right)}\)
\(=6:\frac{9^8.\left(3-9\right)}{9^8.12}\)
\(=6:\frac{9^8.\left(-6\right)}{9^8.12}\)
\(=6:\left(-\frac{6}{12}\right)\)
\(=6:\left(-\frac{1}{2}\right)\)
\(=-12\)
b) 3/5 : ( -1/5-1/6)+3/5:(-1/3-16/15) ( mình chuyển về ps luôn )
=3/5: (-11/30) + 3/5 : (-7/5)
=3/5:[-11/30+(-7/5)]
=3/5:53/30
=18/53
c) (1/2-13/14):5/7-(-2/21+1/7):5/7
= -3/7:5/7-1/21:5/7
=(-3/7-1/21):5/7
=-10/21:5/7
=-2/3
câu b vá c mình làm tắt nha. chúc bạn học tốt
\(-\frac{3}{5}.\frac{5}{7}+-\frac{3}{5}.\frac{3}{7}+-\frac{3}{5}.\frac{6}{7}=-\frac{3}{5}\left(\frac{5}{7}+\frac{3}{7}+\frac{6}{7}\right)=-\frac{3}{5}.2=-\frac{6}{5}\)
\(\frac{1}{3}.\frac{4}{5}+\frac{1}{3}.\frac{6}{5}-\frac{4}{3}=\frac{1}{3}\left(\frac{4}{5}+\frac{6}{5}\right)-\frac{4}{3}=\frac{1}{3}.2-\frac{4}{3}=\frac{2}{3}-\frac{4}{3}=-\frac{2}{3}\)
\(\frac{4}{19}.\frac{-3}{7}+-\frac{3}{7}.\frac{15}{19}+\frac{5}{7}=-\frac{3}{7}\left(\frac{4}{19}+\frac{15}{19}\right)+\frac{5}{7}=-\frac{3}{7}+\frac{5}{7}=\frac{2}{7}\)
\(\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{9}{13}-\frac{5}{9}.\frac{3}{13}=\frac{5}{9}\left(\frac{7}{13}+\frac{9}{13}-\frac{3}{13}\right)=\frac{5}{9}\)
\(a,6\frac{4}{5}-\left(1\frac{2}{3}+3\frac{4}{5}\right)=6\frac{4}{5}-1\frac{2}{3}-3\frac{4}{5}=6\frac{4}{5}-3\frac{4}{5}-1\frac{2}{3}=3-1\frac{2}{3}=\frac{4}{3}\)
\(b,6\frac{5}{7}-\left(1\frac{3}{4}+2\frac{5}{7}\right)=6\frac{5}{7}-2\frac{5}{7}-1\frac{3}{4}=\frac{9}{4}\)
\(c,7\frac{5}{9}-\left(2\frac{3}{4}+3\frac{5}{9}\right)=7\frac{5}{9}-3\frac{5}{9}-2\frac{3}{4}=4-2\frac{3}{4}=\frac{5}{4}\)
mk nghĩ là phần d như thế này cơ \(7\frac{5}{11}\left(2\frac{3}{7}+3\frac{5}{11}\right)\)
\(7\frac{5}{11}-\left(2\frac{3}{7}+3\frac{5}{11}\right)=7\frac{5}{11}-3\frac{5}{11}-2\frac{3}{7}=4-2\frac{3}{7}=\frac{11}{7}\)
Ta có :
\(\frac{\frac{2}{5}-\frac{2}{9}+\frac{2}{11}}{\frac{7}{5}-\frac{7}{9}+\frac{7}{11}}:\frac{\frac{1}{3}-\frac{1}{4}+\frac{1}{5}}{\frac{7}{6}-\frac{7}{8}+\frac{7}{10}}\)
\(=\)\(\frac{2\left(\frac{1}{5}-\frac{1}{9}+\frac{1}{11}\right)}{7\left(\frac{1}{5}-\frac{1}{9}+\frac{1}{11}\right)}:\frac{\frac{1}{3}-\frac{1}{4}+\frac{1}{5}}{\frac{7}{2}\left(\frac{1}{3}-\frac{1}{4}+\frac{1}{5}\right)}\)
\(=\)\(\frac{2}{7}:\frac{2}{7}\)
\(=\)\(\frac{2}{7}.\frac{7}{2}\)
\(=\)\(1\)
Chúc bạn học tốt ~
\(=\frac{2-2+2}{7-7+7}:\frac{\frac{2}{6}-\frac{2}{8}+\frac{2}{10}}{\frac{7}{6}-\frac{7}{8}+\frac{7}{10}}\)
\(=\frac{2}{7}:\frac{2-2+2}{7-7+7}\)
\(=\frac{2}{7}:\frac{2}{7}\)
\(=\frac{2}{7}.\frac{7}{2}\)
\(=\frac{2.7}{7.2}\)
\(=\frac{1.1}{1.1}\)
\(=\frac{1}{1}\)
\(=1\)