Rút gọn phân số:
a. \(\frac{121.75.130}{39.660.11.198}\)
b.\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
c.\(\frac{17.5-17}{3-20}\)
Giúp mình với nhé!
Bài 1: rút gọn phân số
\(1,\frac{9.6-9.3}{18}\) \(5,\frac{2^2.3^2-2.3}{2.3^2}\)
\(2,\frac{17.5-17}{3-20}\) \(6,\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
\(3,\frac{49+7.49}{49}\)
\(4,\frac{153.24-153.11}{7-160}\)
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
Hãy rút gọn phân số
= 2^10*(3^10-3^9)
2^9*3^10
......................................... bn tự giải tiếp đi nhé, mìh bạn rồi
NHỚ CHO MÌH ĐÓ NHA
Rút gọn Thanks
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
\(=\frac{2^{10}\left(3^{10}-3^9\right)}{2^9.3^{10}}\)
\(=\frac{2\left(3^{10}-3^9\right)}{3^{10}}\)
\(=\frac{2.\left(59049-19683\right)}{59049}\)
\(=\frac{2.39366}{59049}\)
\(=\frac{78732}{59049}\)
mình ko biết vì mình mới học lớp 5 thôi
đáp số: mới lớp 5
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}=\frac{2^{10}\left(3^{10}-3^9\right)}{2^9.3^{10}}\)
\(=\frac{2^{10}.3}{2^9.3^{10}}=\frac{2^9.2.3}{2^9.3^9.3}\)
\(=\frac{2}{3^9}\)
Rút gọn:
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}=\frac{2^{10}.3^9\left(3-1\right)}{2^9.3^{10}}=\frac{2^{11}.3^9}{2^9.3^{10}}=\frac{4}{3}\)
Bài: Rút gọn phân số
a) \(\frac{3^{10}.\left(-5\right)^{21}}{\left(-5\right)^{20}.3^{12}}\) c)\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
b)\(\frac{-11^5.13^7}{11^5.13^8}\) d)\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
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
Rút gọn p/s sau:
\(\frac{2^{10}.3^{10}-3^{10}.3^9}{2^9.3^{10}}\)
\(\frac{2^{10}.3^{10}-3^{10}.3^9}{2^9.3^{10}}=\frac{3^{10}\left(2^{10}-3^9\right)}{2^9.3^{10}}\)\(=\)\(\frac{2^{10}-3^9}{2^9}=\frac{2^9.2-3^9}{2^9}=2-3^9\)
\(\frac{2^{10}.3^{10}-3^{10}.3^9}{2^9.3^{10}}=\frac{3^{10}\left(2^{10}-3^9\right)}{2^9.3^{10}}=\frac{2^{10}-3^9}{2^9}\)
1, Rút gọn
\(\frac{374}{506}\); \(\frac{3600-75}{8400-175}\); \(\frac{9^{14}.25^5.8^7}{18^{12}.625^3.24^3}\); \(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
2, Rút gọn 1 cách nhanh nhất
\(\frac{1989.1990+3978}{1992.1991-3984}\)
Rút gọn phân số sau
\(\frac{1989.1990+3978}{1992.1991+3984}\)
\(\frac{3^{10}.\left(-5\right)^{21}}{\left(-5\right)^{20}.3^{12}}\) \(\frac{-11^5.13^7}{11^5.13^8}\)
\(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
\(\left(-\right)\frac{1989\cdot1990+3970}{1992\cdot1991+3984}=\frac{1989\cdot\left(1990+2\right)}{1992\cdot\left(1991+2\right)}=\frac{1989}{1993}\)
\(\left(-\right)\frac{3^{10}\cdot\left(-5\right)^{21}}{\left(-5\right)^{20}\cdot3^{12}}=\frac{3^{10}\cdot\left(-5\right)^{20}\cdot\left(-5\right)}{3^{10}\cdot\left(-5\right)^{20}\cdot3^2}=-\frac{5}{9}\)
\(\left(-\right)\frac{\left(-11\right)^5\cdot13^7}{11^5\cdot13^8}=\frac{11^5\cdot13^7\cdot\left(-1\right)}{11^5\cdot13^7\cdot13}=-\frac{1}{13}\)
\(\left(-\right)\frac{2^{10}\cdot3^{10}-2^{10}\cdot3^9}{2^9\cdot3^{10}}=\frac{2^{10}\cdot3^9\left(3-1\right)}{2^9\cdot3^{10}}=\frac{2^{11}\cdot3^9}{2^9\cdot3^{10}}=\frac{4}{3}\)
So sánh hai phân số:
a) \(\frac{{ - 3}}{8}\) và \(\frac{{ - 5}}{{24}}\) b) \(\frac{{ - 2}}{{ - 5}}\) và \(\frac{3}{{ - 5}}\).
c) \(\frac{{ - 3}}{{ - 10}}\) và \(\frac{{ - 7}}{{20}}\) c) \(\frac{{ - 5}}{4}\) và \(\frac{{23}}{{ - 20}}\).
a) \(\frac{{ - 3}}{8} = \frac{{ - 3.3}}{{8.3}} = \frac{{ - 9}}{{24}}\)
Vì -9 < -5 nên \(\frac{{ - 9}}{{24}} < \frac{{ - 5}}{{24}}\)
Vậy \(\frac{{ - 3}}{8} < \frac{{ - 5}}{{24}}\).
b) Cách 1: \(\frac{{ - 2}}{{ - 5}} = \frac{2}{5}; \frac{3}{{ - 5}} = \frac{-3}{{5}}\)
Vì 2 > -3 nên \(\frac{2}{5} > \frac{-3}{{5}}\)
Vậy \(\frac{{ - 2}}{{ - 5}} > \frac{3}{{ - 5}}\).
Cách 2: \(\frac{{ - 2}}{{ - 5}} = \frac{2}{5} > 0\) mà \(\frac{3}{{ - 5}} < 0\)
\(\Rightarrow\) \(\frac{{ - 2}}{{ - 5}} > \frac{3}{{ - 5}}\).
c) \(\frac{{ - 3}}{{ - 10}} = \frac{3}{{10}} = \frac{{3.2}}{{10.2}} = \frac{6}{{20}}\)
\(\frac{{ - 7}}{{ - 20}} = \frac{7}{{20}}\)
Vì 6 < 7 nên \(\frac{6}{{20}} < \frac{7}{{20}}\) nên \(\frac{{ - 3}}{{ - 10}} < \frac{{ - 7}}{{ - 20}}\).
d) \(\frac{{ - 5}}{4} = \frac{{ - 5.5}}{{4.5}} = \frac{{ - 25}}{{20}}; \frac{{ 23}}{{-20}}=\frac{{-23}}{{20}} \)
Vì -25 < -23 nên \( \frac{{ - 25}}{{20}} < \frac{{-23}}{{20}} \)
Vậy \(\frac{{ - 5}}{4} < \frac{{23}}{{ - 20}}\).