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

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

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

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

đề =\(\frac{\left(3^2\right)^{14}.\left(15^2\right)^5.\left(2^3\right)^7}{\left(2.9\right)^{12}.\left(5^3\right)^3.\left(8.3\right)^3}=\frac{3^{28}.15^{10}.2^{21}}{2^{12}.9^{12}.5^9.\left(2^3\right)^3.3^3}\) 

\(=\frac{3^{28}.3^{10}.5^{10}.2^{21}}{2^{21}.3^{27}.5^9}=\frac{3^{38}.5^{10}.2^{21}}{2^{21}.3^{27}.5^9}=3^9.5\) 

cái này bạn bấm mt là ra nha

k cho mình nha bạn

Đề: \(\frac{9^{14}\cdot225^5\cdot8^7}{18^{12}\cdot625^3\cdot24^3}\)

\(\Rightarrow\frac{\left(3^2\right)^{14}\cdot\left(5.3\right)^5\cdot\left(2^3\right)^7}{\left(3^2\cdot2\right)^{12}\cdot\left(5^4\right)^3\cdot\left(2^3\cdot3\right)^3}\)

\(\Rightarrow\frac{3^{28}\cdot5^5\cdot3^5\cdot2^{21}}{3^{24}\cdot2^{12}\cdot5^{12}\cdot2^9\cdot3^3}\)

\(\Rightarrow\frac{3^{33}\cdot5^5\cdot2^{21}}{3^{27}\cdot2^{21}\cdot5^{12}}\)

\(\Rightarrow\frac{3^{26}}{5^7}\)

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

a/ = -5/9

b/ = 13

c/= 4/3

d/ =5/9

tích đi...^.^!!!

nhìu thế 

đăng từng câu một mới có cơ có người trả lời đó bạn