Question

Tính hợp lý: \(\frac{21^{11}.5-7^{11}.3^{12}}{7^{10}.3^9+21^{10}}\)

Answer 1

\(\frac{21^{11}.5-7^{11}.3^{12}}{7^{10}.3^9+21^{10}}=\frac{7^{11}.3^{11}.5-7^{11}.3^{12}}{7^{10}.3^9+7^{10}.3^{10}}=\frac{7^{11}.3^{11}.\left(5-3\right)}{7^{10}.3^9.\left(1+3\right)}\)

                                            \(=\frac{7^{11}.3^{11}.2}{7^{10}.3^9.4}=\frac{7.3^2}{2}=\frac{7.9}{2}=\frac{63}{2}\)

Answer 2

nhân hết thì lm dc còn có cộng trừ thì hơi khó

Answer 3

Có cộng và trừ ko rút gon đc nhanh

Answer 4

Kẹo dẻo thì bởi z ms cầu cứu nè

Answer 5

\(\frac{21^{11}.5-7^{11}.3^{12}}{7^{10}.3^9+21^{10}}=\frac{\left(3.7\right)^{11}.5-7^{11}.3^{12}}{7^{10}.3^9+\left(3.7\right)^{10}}\)

\(=\frac{3^{11}.7^{11}.5-7^{11}.3^{12}}{7^{10}.3^9+3^{10}.7^{10}}=\frac{3^{11}.7^{11}.\left(5-3\right)}{7^{10}.3^9\left(1+3\right)}\)

\(=\frac{7.3^2.2}{4}=\frac{9.7.2}{4}=\frac{9.7}{2}=\frac{63}{2}\)