\(a,3^2\cdot\frac{1}{243}=3^2\cdot\frac{1}{3^5}=\frac{1}{3^3}=\frac{1^3}{3^3}=\left(\frac{1}{3}\right)^3\)

\(b,81^2\cdot\frac{1}{3^3}=\left(3^4\right)^2\cdot\frac{1}{3^3}=3^8\cdot\frac{1}{3^3}=3^5\)

a) \(3^2.\frac{1}{243}=\frac{1.3^3}{243}=\frac{3^2}{243}=\frac{3^2}{3^5}=\frac{1}{3^3}=\frac{1}{27}\)

b) \(81^2.\frac{1}{3^3}=\frac{1.81^2}{3^3}=\frac{81^2}{3^3}=\frac{3^8}{3^3}=3^5=243\)

2^5.2^4:2^2.1/16=(2^7)/16

\(\frac{32\cdot2^4}{2^2\cdot\frac{1}{16}}\)

\(=\frac{2^5\cdot2^4}{\frac{4}{16}}\)

\(=\frac{2^9}{\frac{1}{4}}\)

\(=2^9\cdot4\)

\(=2^9\cdot2^2\)

\(=2^{11}\)

=32 X 16 : ( 4 X 1/16)=2048

    32 . 2⁴ : ( 2² . 1/16 ) 

=  2⁵ . 2⁴ : 1/2²

=  2⁹ . 2²

= 2¹¹

\(\frac{2^7}{16}\)

\(2^{11}\)

mình sẽ k cho 3 bạn làm nhanh nhất nhé , giúp mình nha các bạn. thanks các bạn nhé

lười quá, thầy cũng cho mấy dạng này lười đánh máy quá

a, \(\frac{25.5^3.1}{25.5^2}=\frac{5^2.5^3.1}{5^2.5^2}=\frac{5^5}{5^4}=5\)

b, \(5^2.3^5.\left(\frac{3}{5}\right)^2=5^2.3^5.\frac{9}{25}=5^2.\frac{9}{25}.3^5=9.3^5=3^2.3^5=3^7\)

c, \(\left(\frac{1}{7}\right)^2\cdot\frac{1}{7}\cdot\frac{49}{2}=\frac{1}{49}\cdot\frac{1}{7}\cdot\frac{49}{2}=\frac{1}{49}\cdot\frac{49}{2}\cdot\frac{1}{7}=\frac{1}{2}\cdot\frac{1}{7}=\frac{1}{14}\)

=(1/2) mu 15*(1/2 mu 2) mu 20

=1/2 mu 15*1/2 mu 40

=1/2 mu 55

Dung thi k ung ho minh nha!Thanks!!!