Question

[Hanh]

Thực hiện các phép tính sau bằng cách hợp lý

( 8²⁰¹⁷ - 8²⁰¹⁵⁾ : ( 8²⁰¹⁴ . 8 )

( 2⁸ + 8³ ) : ( 2⁵ . 2³)

Answer 1

[乡☪ɦαทɦ💥☪ɦųα✔]

\(a,\frac{8^{2017}-8^{2015}}{8^{2014}.8}\)

\(=\frac{8^{2015}.\left(8^2-1\right)}{8^{2015}}\)

\(=64-1\)

\(=63\)

\(b,\frac{2^8+8^3}{2^5.2^3}\)

\(=\frac{2^8+\left(2^3\right)^3}{2^8}\)

\(=\frac{2^8+2^9}{2^8}\)

\(=\frac{2^8.\left(1+2\right)}{2^8}\)

\(=3\)

Học tốt

Answer 2

[Huỳnh Quang Sang]

8²⁰¹⁷ - 8²⁰¹⁵ = 8²⁰¹⁵(8² - 1) = 8²⁰¹⁵.63

8²⁰¹⁴.8 = 8²⁰¹⁴⁺¹ = 8²⁰¹⁵

=> \(\frac{8^{2017}-8^{2015}}{8^{2014}\cdot8}=\frac{8^{2015}\cdot63}{8^{2015}}=63\)

2⁸ + 8³ = 2⁸ + (2³)³ = 2⁸ + 2⁹ = 2⁸(1 + 2) = 2⁸.3

2⁵.2³ = 2⁵⁺³ = 2⁸

=> \(\frac{2^8+8^3}{2^5\cdot2^3}=\frac{2^8\cdot3}{2^8}=3\)