\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
rút gọn
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
=\(\frac{5^{11}.7^{11}\left(7+1\right)}{5^{11}.7^{11}\left(5.7+9\right)}\)
= \(\frac{8}{35+9}\)
= \(\frac{8}{44}\)
= \(\frac{2}{11}\)
rút gọn:\(\frac{5^{11}.7^{12}+5^{11}-7^{10}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
\(\frac{5^{11}.7^{12}+5^{11}.7^{10}}{5^{12}.7^{12}+9.5^{11}.7^{11}}=\frac{5^{11}7^{10}\left(7^2+1\right)}{5^{11}7^{11}\left(5.7+9\right)}=\frac{50}{7.44}=\frac{25}{154}\)
Rút gọn:
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
rút gọn phân số: \(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}=\frac{5^{11}.7^{11}.\left(7+1\right)}{5^{11}.7^{11}\left(5.7+9\right)}=\frac{8}{35+9}=\frac{8}{44}=\frac{2}{11}\)
marion loz gì đó... bạn nói cái đách lone gì vậy?
Rút gọn:
\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{11}+9.5^{11}.7^{11}}\)
\(\frac{5^{11}\cdot7^{12}+5^{11}\cdot7^{11}}{5^{12}\cdot7^{11}+9\cdot5^{11}\cdot7^{11}}\)
=\(\frac{5^{11}\cdot\left(7^{12}+7^{11}\right)}{5^{11}\left(5\cdot7^{11}+9\cdot7^{11}\right)}\)
=\(\frac{7^{12}+7^{11}}{5\cdot7^{11}+9\cdot7^{11}}\)
=\(\frac{7^{11}\left(7+1\right)}{7^{11}\left(5+9\right)}\)
=\(\frac{8}{14}=\frac{4}{7}\)
Kết quả này chắc chắn là đúng đấy
a,\(\dfrac{121.75.130.169}{39.60.11.198}\)
b,\(\dfrac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}.9.5^{11}.7^{11}}\)
a
\(\dfrac{121.75.130.169}{39.60.11.198}\\ =\dfrac{11.11.5.5.3.13.2.5.13.13}{13.3.2.2.3.5.11.18.11}\\ =\dfrac{5.13.5.13}{2.3.18}\\ =\dfrac{65.65}{108}\\ =\)
tự tính
\(b\\ \dfrac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}.9.5^{11}.7^{11}}\\ =\dfrac{5^{11}.7^{11}.2.7}{5^{12}.7^{11}.7.9.5^{11}.7^{11}}\\ =\dfrac{2}{5^{12}.7^{11}.9.}\\ =\)\
tự tính nhé
Rút gọn phân số: 511.712.511.711 / 512.712.9.511.711
\(\frac{5^{11}.7^{12}.5^{11}.7^{11}}{5^{12}.7^{12}.9.5^{11}.7^{11}}\)=\(\frac{1}{45}\)
Bài 1: rút gọn các phân số sau:
a) \(\frac{3^{10}.\left(-5\right)^{21}}{\left(-5\right)^{20}.3^{12}}\)
b) \(\frac{-11^5.13^7}{11^5.13^8}\)
c) \(\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}\)
d) \(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)
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