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Rút gọn phân số  -11^5.13^7/11^5.13^8 

Ai dải đúng mình sẽ k

\(\frac{\left(-11\right)^5.13^7}{11^5.13^8}=\frac{\left(-11\right)^5.13^7}{11^5.13^7}.\frac{1}{13}=-1.\frac{1}{13}=-\frac{1}{13}\)

(-11)⁵x13⁷/11⁵.13⁸=-1/13⁸

Chúc bạn học giỏi nha!!!

\(\frac{-11^5.13^7}{11^5.13^8}=\frac{-11^4.\left(-11\right).13^7}{11^4.11.13^7.13}=\frac{-11}{11.13}=\frac{-11}{143}\)

bằng -1/13

                                      ko tik xui nguyên năm gán chịu

\(\frac{-11^5.13^7}{11^5.13^8}=\frac{\left(-1\right).11^5.13^7}{11^5.13^7.13}=\frac{-1}{13}\)

\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}=\frac{2^{10}.\left(3^{10}-3^9\right)}{2^9.3^{10}}=\frac{2^9.2.3^9.\left(3-1\right)}{2^9.3.3^9}=\frac{2.2}{3}=\frac{4}{3}\)

a, \(\frac{-11^5.13^7}{11^5.13^8}=\frac{-1}{13}\)

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

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

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

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

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

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