Question

[Triệu Thùy Linh]

Rút gọn

\(\frac{9^2.\left(-4\right)^5.72}{5.\left(-6\right)^6}.\frac{6^3.81.\left(-4\right)}{\left(-8\right)^6.3^9}\)

Answer 1

[Ngô Chi Lan]

Bài làm:

Ta có: \(\frac{9^2.\left(-4\right)^5.72}{5.\left(-6\right)^6}\cdot\frac{6^3.81.\left(-4\right)}{\left(-8\right)^6.3^9}\)

\(=\frac{3^2.-2^{10}.2^3.3^2.2^3.3^3.3^4.-2^2}{5.2^3.3^3.2^{18}.3^9}\)

\(=\frac{2^{18}.3^{11}}{2^{21}.3^{12}.5}\)

\(=\frac{1}{2^3.2.5}=\frac{1}{120}\)

Answer 2

[Nguyễn Viết Tùng]

\(\frac{25^5.2^{10}}{20^4.5^4}\)

=\(\frac{25^5.2^{10}}{20^4.25^2}\)

=\(\frac{25^3.2^{10}}{20^4}\)

=\(\frac{25^3.1024}{160000}\)

=\(\frac{25^3.4}{25^2}\)

=\(25.4\)

=100