bài 1: tính
a) \(\left(\frac{3}{7}\right)^0=\frac{7}{9}:\left(\frac{2}{3}\right)^2-\left|-\frac{4}{5}\right|\)
b) \(\frac{10^3+2.5^3+5^3}{55}\)
bài 2: so sánh
\(^{3^{2009}}\) và \(9^{1005}\)
thanksss~~~
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a)
\(\begin{array}{l}\frac{1}{9} - 0,3.\frac{5}{9} + \frac{1}{3}\\ = \frac{1}{9} - \frac{3}{{10}}.\frac{5}{9} + \frac{1}{3}\\ = \frac{1}{9} - \frac{3}{{2.5}}.\frac{5}{{3.3}} + \frac{1}{3}\\ = \frac{1}{9} - \frac{1}{6} + \frac{1}{3}\\ = \frac{2}{{18}} - \frac{3}{{18}} + \frac{6}{{18}}\\ = \frac{5}{{18}}\end{array}\)
b)
\(\begin{array}{l}{\left( {\frac{{ - 2}}{3}} \right)^2} + \frac{1}{6} - {\left( { - 0,5} \right)^3}\\ = \frac{4}{9} + \frac{1}{6} - \left( {\frac{{ - 1}}{2}} \right)^3\\ = \frac{4}{9} + \frac{1}{6} - \left( {\frac{{ - 1}}{8}} \right)\\ = \frac{4}{9} + \frac{1}{6} + \frac{1}{8}\\ = \frac{{32}}{{72}} + \frac{{12}}{{72}} + \frac{9}{{72}}\\ = \frac{{53}}{{72}}\end{array}\)
\(A=9-\frac{3}{5}+\frac{2}{3}-7-\frac{7}{5}+\frac{3}{2}-3+\frac{9}{5}-\frac{5}{2}\)
\(=\left(9-7-3\right)+\left(\frac{9}{5}-\frac{7}{5}-\frac{3}{5}\right)+\left(\frac{3}{2}-\frac{5}{2}\right)\)
\(=-2-\frac{1}{5}=-\frac{11}{5}\)
\(\frac{-2}{3}-\left(\frac{-2}{5}\right)-\frac{7}{10}\)
\(=\frac{-10}{15}-\frac{-6}{15}-\frac{7}{10}\)
\(=\frac{-4}{15}-\frac{7}{10}\)
\(=\frac{-4}{15}+\frac{\left(-7\right)}{10}\)
\(=\frac{-40}{150}+\frac{-105}{150}\)
\(=\frac{-29}{30}\)
\(\left[\frac{11}{24}:\frac{55}{36}\right]\cdot\frac{10}{3}\)
\(=\left[\frac{11}{24}\cdot\frac{36}{55}\right]\cdot\frac{10}{3}\)
\(=\left[\frac{1}{2}\cdot\frac{3}{5}\right]\cdot\frac{10}{3}\)
\(=\frac{3}{10}\cdot\frac{10}{3}=1\)
a.
\(\left(\frac{3}{7}\right)^0+\frac{7}{9}\div\left(\frac{2}{3}\right)^2-\left|-\frac{4}{5}\right|=0+\frac{7}{9}\div\frac{4}{9}-\frac{4}{5}=\frac{7}{9}\times\frac{9}{4}-\frac{4}{5}=\frac{7}{4}-\frac{4}{5}=\frac{35}{20}-\frac{16}{20}=\frac{19}{20}\)
b.
\(\frac{10^3+2\times5^3+5^3}{55}=\frac{\left(2\times5\right)^3+2\times5^3+5^3}{55}=\frac{2^3\times5^3+2\times5^3+5^3}{5\times11}=\frac{5^3\times\left(2^3+2+1\right)}{5\times11}=\frac{5^2\times11}{11}=5^2=25\)
c.
\(3^{2009}< 3^{2010}=\left(3^2\right)^{1005}=9^{1005}\)
Vậy 32009 < 91005
Chúc bạn học tốt ^^