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Bạn tham khảo nhé
a ) Ta có :
\(\left(-\frac{1}{5}\right)^{300}=\left(\frac{1}{5}\right)^{300}=\frac{1}{5^{300}}=\frac{1}{\left(5^3\right)^{100}}=\frac{1}{125^{100}}\)
\(\left(-\frac{1}{3}\right)^{500}=\left(\frac{1}{3}\right)^{500}=\frac{1}{3^{500}}=\frac{1}{\left(3^5\right)^{100}}=\frac{1}{243^{100}}\)
Do \(\frac{1}{125^{100}}>\frac{1}{243^{100}}\left(125^{100}< 243^{100}\right)\)
\(\Rightarrow\left(-\frac{1}{5}\right)^{300}>\left(-\frac{1}{3}\right)^{500}\)
b )
Ta có :
\(2550^{10}=\left(50.51\right)^{10}=50^{10}.51^{10}\)
\(50^{20}=50^{10}.50^{10}\)
Do \(50^{10}.51^{10}>50^{10}.50^{10}\)
\(\Rightarrow50^{20}< 2550^{10}\)
c )
Ta có :
\(2^{100}=\left(2^4\right)^{25}=16^{25}\)
\(3^{75}=\left(3^3\right)^{25}=27^{25}\)
\(5^{50}=\left(5^2\right)^{25}=25^{25}\)
Do \(16^{25}< 25^{25}< 27^{25}\)
\(\Rightarrow2^{100}< 5^{50}< 3^{75}\)
a)\(\left(\frac{-1}{3}\right)^3\cdot x=\frac{1}{81}\) \(< =>\frac{-1}{27}x=\frac{1}{81}\)\(< =>x=\frac{-1}{3}\)
Bài giải
\(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot\cdot\cdot\left(1-\frac{1}{2012}\right)\)
\(=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot...\cdot\frac{2011}{2012}\)
\(=\frac{1\cdot2\cdot3\cdot...\cdot2011}{2\cdot3\cdot4\cdot...\cdot2012}\)
\(=\frac{1}{2012}\)
Bài giải
\(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot\cdot\cdot\left(1-\frac{1}{2012}\right)\)
\(=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot...\cdot\frac{2011}{2012}\)
\(=\frac{1\cdot2\cdot3\cdot...\cdot2011}{2\cdot3\cdot4\cdot...\cdot2012}\) ( Sử dụng phương pháp khử )
\(=\frac{1}{2012}\)
=\(\left(6.\frac{1}{4}+1+1\right):\left(\frac{-1}{2}-1\right)\)
=\(\frac{5}{2}\):\(\frac{\left(-3\right)}{2}\)=\(\frac{-10}{6}=\frac{-5}{3}\)
hok tốt
\(\left[6.\left(-\frac{1}{2}\right)^2-2.\left(-\frac{1}{2}\right)+1\right].\left(-\frac{1}{2}-1\right)\)
\(=\left(6.\frac{1}{4}-\left(-1\right)+1\right).\left(-\frac{3}{2}\right)\)
\(=\frac{3}{2}.\left(-\frac{3}{2}\right)\)
\(=-\frac{9}{4}\)
~Moon~
a) \(\left[-\frac{1}{2}\left(a-1\right)x^3y^4z^2\right]^5=\frac{-\left(a-1\right)^5}{32}x^{15}y^{20}z^{10}\)
Hệ số: \(\frac{-\left(a-1\right)^5}{32}\). Bậc của đơn thức: \(15+20+10=45\)
b) \(\left(a^5b^2xy^2z^{n-1}\right)\left(-b^3cx^4z^{7-n}\right)=-a^5b^5cx^5y^2z^6\)
Hệ số: \(-a^5b^5c\). Bậc của đơn thức: \(5+2+6=13\)
c) \(\left(-\frac{9}{10}a^3x^2y\right)\left(-\frac{5}{3}ax^5y^2z\right)^3=\left(-\frac{9}{10}a^3x^2y\right)\left(-\frac{125}{27}a^3x^{15}y^6z^3\right)\)\(=\frac{25}{6}a^6x^{17}y^7z^3\)
Hệ số: \(\frac{25}{6}a^6\). Bậc của đơn thức:\(17+7+3=27\)
Bạn tham khảo ở đây nhé, mình làm rồi đấy: https://olm.vn/hoi-dap/detail/211418926066.html
a) \(\left(x-\frac{1}{2}\right)^4=\frac{1}{81}\)
\(\Rightarrow\left(x-\frac{1}{2}\right)^4=\left(\frac{1}{3}\right)^4\)
\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{2}=\frac{1}{3}\\x-\frac{1}{2}=\frac{-1}{3}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{5}{6}\\x=\frac{1}{6}\end{cases}}\)
Vậy ...
\(\left(\frac{1}{3}\right)^{202}=\left[\left(\frac{1}{3}\right)^2\right]^{101}=\left(\frac{1}{9}\right)^{101}=\frac{1}{9^{101}}\)
\(\left(\frac{1}{2}\right)^{303}=\left[\left(\frac{1}{2}\right)^3\right]^{101}=\left(\frac{1}{8}\right)^{101}=\frac{1}{8^{101}}\)
Ta có: \(9>8\Rightarrow9^{101}>8^{101}\Rightarrow\frac{1}{9^{101}}< \frac{1}{8^{101}}\)
\(\Rightarrow\left(\frac{1}{2}\right)^{303}>\left(\frac{1}{3}\right)^{202}\)