\(A=\frac{2^{12}.3^5-4^6.81}{\left(2^2.3\right)^6+8^4.3^5}=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}=\frac{2^{12}.3^4\left(3-1\right)}{2^{12}.3^5\left(3+1\right)}=\frac{2}{3.4}=\frac{1}{6}\)

=\(\frac{2^{12}.3^5+2^{12}.3^4}{2^{12}.3^6+2^{12}.3^3}\)

=\(\frac{2^{12}\left(3^5+3^4\right)}{2^{12}\left(3^6+3^3\right)}\)

\(=\frac{324}{756}\)

=\(\frac{3}{7}\)

                                                                 Bài giải

\(\frac{2^{12}\cdot3^5-4^6\cdot81}{\left(2^2\cdot6\right)^6+8^4\cdot3^5}=\frac{2^{12}\cdot3^5-\left(2^2\right)^6\cdot3^4}{2^{12}\cdot6^6+\left(2^3\right)^4\cdot3^5}=\frac{2^{12}\cdot3^5-2^{12}\cdot3^4}{2^{12}\cdot2^6\cdot3^6+2^{12}\cdot3^5}=\frac{2^{12}\cdot3^4\left(3-1\right)}{2^{12}\cdot3^4\left(2^6\cdot3^2+3\right)}\)

\(=\frac{2}{64\cdot9+3}=\frac{2}{576+3}=\frac{2}{579}\)

\(=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}-\frac{5^{10}.7^3-5^{10}.7^4}{5^9.7^3+5^4.2^3.7^3}\)

\(=\frac{2^{12}.3^4\left(3-1\right)}{2^{12}.3^5\left(3+1\right)}-\frac{5^{10}.7^3\left(1-7\right)}{5^4.7^3\left(5^5+2^3\right)}\)

\(=\frac{1}{6}+\frac{93750}{3133}\)

tối mk làm cho nha, giờ mk đg bận, sorry

\(\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)+8^4.3^5}\)

\(\frac{2^{12}.3^5-\left(2^2\right)^6.\left(3^2\right)^2}{2^2.3+2^4.3^4.3^5}\)

\(\frac{2^{12}.3^5-2^{12}.3^4}{2^2.3+2^4.3^{20}}\)

\(\frac{2^{12}.3^4\left(3-1\right)}{2^2.3\left(1+2^2.3^{19}\right)}\)

\(\frac{2^{10}.3^2.4}{1+2^2.3^{19}}\)

bn tự giải tiếp nha mk phải có việc rồi nếu ko lm đc thì kb với mk tối mk giải cho nha

\(\frac{2^{12}.3^5-4^6.81}{\left(2^2.3\right)^6+8^4.3^5}\)

\(=\frac{2^{12}.3^5-2^{12}.3^4}{2^{12}.3^6+2^{12}.3^5}\)

\(=\frac{2^{12}.\left(3^5-3^4\right)}{2^{12}.\left(3^6+3^5\right)}\)

\(=\frac{3^5-3^4}{3^6+3^5}=\frac{3^4.\left(3-1\right)}{3^5\left(3+1\right)}\)

\(=\frac{3^4.2}{3^5.4}=\frac{3^4.2}{3^4.3.4}=\frac{2}{12}=\frac{1}{6}\)

P/s: Hoq chắc ạ (: Ms lp 6 lm đại

\(\frac{x}{2}=\frac{y}{3}\)

\(\Leftrightarrow\frac{x}{8}=\frac{y}{12}\)(1)

\(\frac{y}{4}=\frac{z}{5}\)

\(\Leftrightarrow\frac{y}{12}=\frac{z}{15}\)(2)

Từ (1) (2)

 \(\Rightarrow\frac{x}{8}=\frac{y}{12}=\frac{z}{15}=\frac{x+y-z}{8+12-15}=\frac{10}{5}=2\)

\(\Rightarrow\hept{\begin{cases}x=2.8\\y=2.12\\z=2.15\end{cases}\Rightarrow}\hept{\begin{cases}x=16\\y=24\\z=30\end{cases}}\)

a) P = 2x + 2xy - y

|x| = 2,5 => x thuộc { 2,5; -2,5 }

* TH1 : x = 2,5 và y = -0,75

Thay vào P ta có :

P = 2 . 2,5 + 2 . 2,5 . (-0,75) - ( -0,75 ) 

P = 2

* TH2 : x = -2,5 và y = -0,75

Thay vào P ta có :

P = 2 . ( -2,5 ) + 2 . ( -2,5 ) . ( -0,75 ) - ( -0,75 )

P = -0,5

Vậy.....

b) \(Q=\frac{2^{12}\cdot3^5-4^6\cdot81}{\left(2^2\cdot3\right)^6+8^4\cdot3^5}\)

\(Q=\frac{2^{12}\cdot3^5-2^{12}\cdot3^4}{2^{12}\cdot3^6+2^{12}\cdot3^5}\)

\(Q=\frac{2^{12}\cdot3^4\cdot\left(3-1\right)}{2^{12}\cdot3^5\cdot\left(3+1\right)}\)

\(Q=\frac{2}{3\cdot4}\)

\(Q=\frac{1}{3\cdot2}\)

\(Q=\frac{1}{6}\)

p/s: P làm Q, Q làm P :D