Question

[Nguyễn Thị Huế]

Rút gọn

\(A=\frac{a^2.a^7.b^2.c^8}{a^5.b^3.\left(-c\right)^4}\) 

B=\(\left(\frac{3}{7}\right)^{5.}\frac{\left(25\right)^4.7^5}{15^4.20^2}\)

Answer 1

[Phan Văn Hiếu]

ý B hình như mk giải rồi thì phải

Answer 2

[Ngọc Vĩ]

\(A=\frac{a^2.a^7.b^2.c^8}{a^5.b^3.\left(-c\right)^4}=\frac{a^9.b^2.c^8}{a^5.b^3.c^4}=\frac{a^4.c^4}{b}\)

\(B=\left(\frac{3}{7}\right)^5.\frac{\left(25\right)^4.7^5}{15^4.20^2}=\frac{3^5.\left(5^2\right)^4.7^5}{7^5.\left(3.5\right)^4.\left(4.5\right)^2}=\frac{3^5.5^8.7^5}{7^5.3^4.5^4.4^2.5^2}\)

    \(=\frac{3^5.5^8.7^5}{7^5.3^4.5^6.4^2}=\frac{3.5^2}{4^2}=\frac{75}{16}\)