giúp mình nhé (. là nhân nhé)
1.thực hiện phép tính
a)\(\dfrac{3}{14}\).\(\dfrac{7}{20}\)+\(\dfrac{13}{20}\)
b)(2.3\(^{2010}\)+12.3\(^{2010}\)-3.3\(^{2010}\)):3\(^{2012}\)
2.viết các kết quả của biểu thức sau dưới dạng 1 lũy thừa
a)(5\(^{14}\).25\(^{10}\)):125\(^3\)
b)(\(\dfrac{1}{2}\))\(^5\).(\(\dfrac{1}{64}\))\(^9\):(\(\dfrac{1}{16}\))\(^5\)
Bài 1.
a) \(\dfrac{3}{14}.\dfrac{7}{20}+\dfrac{13}{20}=\dfrac{3}{40}+\dfrac{13}{20}=\dfrac{3}{40}+\dfrac{26}{40}=\dfrac{29}{40}\).
b) \(\left(2.3^{2010}+12.3^{2010}-3.3^{2010}\right):3^{2012}\)
\(=3^{2010}\left(2+12-3\right):3^{2012}\)
\(=3^{2010}.11:3^{2012}\)
\(=\left(3^{2010}:3^{2012}\right).11\)
\(=\dfrac{1}{9}.11\)
\(=\dfrac{11}{9}\).
Bài 2.
a) \(\left(5^{14}.25^{10}\right):125^3\)
\(=\left[5^{14}.\left(5^2\right)^{10}\right]:\left(5^3\right)^3\)
\(=\left[5^{14}.5^{20}\right]:5^9\)
\(=5^{34}:5^9\)
\(=5^{25}\).
b) \(\left(\dfrac{1}{2}\right)^5.\left(\dfrac{1}{64}\right)^9:\left(\dfrac{1}{16}\right)^5\)
\(=\dfrac{1}{2^5}.\dfrac{1}{64^9}:\dfrac{1}{16^5}\)
\(=\dfrac{1}{2^5}.\dfrac{1}{\left(2^6\right)^9}:\dfrac{1}{\left(2^4\right)^5}\)
\(=\dfrac{1}{2^5}.\dfrac{1}{2^{54}}:\dfrac{1}{2^{20}}\)
\(=\dfrac{1}{2^{59}}:\dfrac{1}{2^{20}}\)
\(=\dfrac{2^{20}}{2^{59}}\)
\(=\dfrac{1}{2^{39}}\).
