\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)

\(=\frac{2^{10}\left(3^{10}-3^9\right)}{2^9.3^{10}}\)

\(=\frac{2\left(3^{10}-3^9\right)}{3^{10}}\)

\(=\frac{2.\left(59049-19683\right)}{59049}\)

\(=\frac{2.39366}{59049}\)

\(=\frac{78732}{59049}\)

mình ko biết vì mình mới học lớp 5 thôi

                               đáp số: mới lớp 5 

\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}=\frac{2^{10}.3^9\left(3-1\right)}{2^9.3^{10}}=\frac{2^{11}.3^9}{2^9.3^{10}}=\frac{4}{3}\)

tinh song roi rut gon 

a)\(\frac{ }{ }\)

a) \(\frac{25}{1188}\)

b)\(\frac{4}{3}\)

c)\(\frac{17\times4}{-17}=\frac{4}{-1}=\frac{-4}{1}=-4\)

\(\frac{2^{10}.3^{10}-3^{10}.3^9}{2^9.3^{10}}=\frac{3^{10}\left(2^{10}-3^9\right)}{2^9.3^{10}}\)\(=\)\(\frac{2^{10}-3^9}{2^9}=\frac{2^9.2-3^9}{2^9}=2-3^9\)

\(\frac{2^{10}.3^{10}-3^{10}.3^9}{2^9.3^{10}}=\frac{3^{10}\left(2^{10}-3^9\right)}{2^9.3^{10}}=\frac{2^{10}-3^9}{2^9}\)

\(\left(-\right)\frac{1989\cdot1990+3970}{1992\cdot1991+3984}=\frac{1989\cdot\left(1990+2\right)}{1992\cdot\left(1991+2\right)}=\frac{1989}{1993}\)

\(\left(-\right)\frac{3^{10}\cdot\left(-5\right)^{21}}{\left(-5\right)^{20}\cdot3^{12}}=\frac{3^{10}\cdot\left(-5\right)^{20}\cdot\left(-5\right)}{3^{10}\cdot\left(-5\right)^{20}\cdot3^2}=-\frac{5}{9}\)

\(\left(-\right)\frac{\left(-11\right)^5\cdot13^7}{11^5\cdot13^8}=\frac{11^5\cdot13^7\cdot\left(-1\right)}{11^5\cdot13^7\cdot13}=-\frac{1}{13}\)

\(\left(-\right)\frac{2^{10}\cdot3^{10}-2^{10}\cdot3^9}{2^9\cdot3^{10}}=\frac{2^{10}\cdot3^9\left(3-1\right)}{2^9\cdot3^{10}}=\frac{2^{11}\cdot3^9}{2^9\cdot3^{10}}=\frac{4}{3}\)

Hai câu a) và b) bạn chỉ cần xem số mũ rồi trừ số mũ là xong 

\(c)\) \(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}=\frac{2^{10}.3^9\left(3-1\right)}{2^9.3^{10}}=\frac{2^{10}.3^9.2}{2^9.3^{10}}=\frac{2^{11}.3^9}{2^9.3^{10}}=\frac{2^2}{3}=\frac{4}{3}\)

\(d)\) \(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}=\frac{5^{11}.7^{11}\left(7+1\right)}{5^{11}.7^{11}\left(5.7+9\right)}=\frac{8}{35+9}=\frac{8}{44}=\frac{2}{11}\)

Chúc bạn học tốt 

Ta có : 21^0.3^10−2^10.3^9/2^9.3^10
=> 2^10.(3^10−3^9)/2^9.3^10
=> 2^10.3/2^9.3^10
=> 2/3^9=2/19683

Bài làm

\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)

\(=\frac{2^{10}\left(3^{10}-3^9\right)}{2^9.3^{10}}\)

\(=\frac{2\left[3^9\left(3-1\right)\right]}{3^{10}}\)

\(=\frac{2\left[3^9.2\right]}{3^{10}}\)

\(=\frac{4.3^9}{3^{10}}\)

\(=\frac{4}{3}\)

Vậy giá tị biểu thức là \(\frac{4}{3}\)

4/3 nha bạn