\(A=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-\frac{64}{34}+\frac{14}{21}=\left(\frac{15}{34}+\frac{9}{34}-\frac{64}{34}\right)+\left(\frac{7}{21}+\frac{14}{21}\right)=\frac{30}{34}+\frac{21}{21}=\frac{15}{17}+1=\frac{32}{17}\)

b, 0,5 .\(\sqrt{100}\)-\(\sqrt{\frac{1}{4}}\)

=\(\frac{1}{2}\).10-\(\frac{1}{2}\)

=\(\frac{1}{2}\).(10-1)

=\(\frac{1}{2}\).9

=\(\frac{9}{2}\)

cho mk xl nguyen hong long Nguyễn Kim Chi

Bài 1:

a) \(0,5-\frac{5}{41}+\frac{1}{2}-\frac{36}{41}\)

\(=\frac{1}{2}-\frac{5}{41}+\frac{1}{2}-\frac{36}{41}\)

\(=\left(\frac{1}{2}+\frac{1}{2}\right)-\left(\frac{5}{41}+\frac{36}{41}\right)\)

\(=1-1\)

\(=0.\)

b) \(\left(-\frac{2}{3}+\frac{3}{7}\right):\frac{4}{5}+\left(-\frac{1}{3}+\frac{4}{7}\right):\frac{4}{5}\)

\(=-\frac{2}{3}+\frac{3}{7}:\frac{4}{5}-\frac{1}{3}+\frac{4}{7}:\frac{4}{5}\)

\(=\left[\left(-\frac{2}{3}\right)-\frac{1}{3}\right]+\left(\frac{3}{7}+\frac{4}{7}\right):\frac{4}{5}\)

\(=\left(-1\right)+1:\frac{4}{5}\)

\(=\left(-1\right)+\frac{5}{4}\)

\(=\frac{1}{4}.\)

c) \(\left(-\frac{3}{4}\right).\sqrt{\frac{16}{9}+3.\sqrt{49}}\)

\(=\left(-\frac{3}{4}\right).\sqrt{\frac{16}{9}+3.7}\)

\(=\left(-\frac{3}{4}\right).\sqrt{\frac{16}{9}+21}\)

\(=\left(-\frac{3}{4}\right).\sqrt{\frac{205}{9}}\)

\(=\left(-\frac{3}{4}\right).\frac{\sqrt{205}}{3}\)

\(=-\frac{\sqrt{205}}{4}.\)

d) \(\left(-\frac{1}{3}\right)^2.\frac{4}{11}+1\frac{5}{11}.\left(\frac{1}{3}\right)^2\)

\(=\frac{1}{9}.\frac{4}{11}+\frac{16}{11}.\frac{1}{9}\)

\(=\frac{1}{9}.\left(\frac{4}{11}+\frac{16}{11}\right)\)

\(=\frac{1}{9}.\frac{20}{11}\)

\(=\frac{20}{99}.\)

Chúc bạn học tốt!

cảm ơn bạn

\(\left(\frac{3}{7}-\frac{5}{2}-\frac{3}{5}\right)-\left(-\frac{4}{7}-\frac{3}{2}+\frac{2}{5}\right)=\frac{3}{7}-\frac{5}{2}-\frac{3}{5}+\frac{4}{7}+\frac{3}{2}-\frac{2}{5}\)

                                                                                  \(=\left(\frac{3}{7}+\frac{4}{7}\right)+\left(-\frac{5}{2}+\frac{3}{2}\right)+\left(-\frac{3}{5}-\frac{2}{5}\right)\)

                                                                                  \(=1+\left(-1\right)+\left(-1\right)\)

                                                                                  \(=-1\)

Hok tốt nha^^

a) 12. \(\frac{4}{9}\)+\(\frac{4}{3}\)=\(\frac{16}{3}\)+\(\frac{4}{3}\)=\(\frac{20}{3}\)

b) (\(\frac{-5}{7}\)) . (12,5+1,5)= (\(\frac{-5}{7}\)).14=-10

a) \(12.\left(-\frac{2}{3}\right)^2+\frac{4}{3}=12.\frac{4}{9}+\frac{4}{3}=\frac{16}{3}+\frac{4}{3}=\frac{20}{3}\)

b) \(12,5.\left(-\frac{5}{7}\right)+1,5.\left(-\frac{5}{7}\right)=-\frac{5}{7}.\left(12,5+1,5\right)=-\frac{5}{7}.14=-10\)

c) \(1:\left(\frac{2}{3}-\frac{3}{4}\right)^2=1:\left(-\frac{1}{12}\right)^2=1:\frac{1}{144}=1.144=144\)

d) \(15.\left(-\frac{2}{3}\right)^2-\frac{7}{3}=15.\frac{4}{9}-\frac{7}{3}=\frac{20}{3}-\frac{7}{3}=\frac{13}{3}\)

e) \(\frac{1}{2}\sqrt{64}-\sqrt{\frac{4}{25}}+\left(-1\right)^{2007}=\frac{1}{2}.8-\frac{2}{5}+\left(-1\right)=4-\frac{2}{5}-1=\frac{13}{5}\)

a) \(\frac{3}{5}+\frac{1}{10}-\frac{6}{5}\)

\(=\left(\frac{3}{5}-\frac{6}{5}\right)+\frac{1}{10}\)

\(=\left(-\frac{3}{5}\right)+\frac{1}{10}\)

\(=-\frac{1}{2}.\)

b) \(1\frac{3}{4}.\frac{2}{7}+1\frac{3}{4}.\frac{5}{7}\)

\(=1\frac{3}{4}.\left(\frac{2}{7}+\frac{5}{7}\right)\)

\(=1\frac{3}{4}.1\)

\(=\frac{7}{4}.1\)

\(=\frac{7}{4}.\)

c) Sao lại có dấu chấm phẩy thế kia?

Chúc bạn học tốt!

a) \(\frac{3}{5}+\frac{1}{10}-\frac{6}{5}=\frac{6+1-12}{10}=\frac{-5}{10}=\frac{-1}{2}\)

b) \(1\frac{3}{4}.\frac{2}{7}+1\frac{3}{4}.\frac{5}{7}=1\frac{3}{4}\left(\frac{2}{7}+\frac{5}{7}\right)=1\frac{3}{4}.1=1\frac{3}{4}=\frac{7}{4}\)

c)\(\left(\frac{3}{4}\right)^2.\sqrt{16}+\left[\left(-2\right)^3:\left(-8\right)-1^{2019}\right]=\frac{9}{16}.4+\left[\left(-8\right):\left(-8\right)-1\right]=\frac{9}{16}.4=\frac{9}{4}\)