Question

Thực hiện phép tính :

a) \(\left(7.3^5-3^4+3^6\right):3^4\)

b) \(\left(16^3-64^2\right):8^3\)

Answer 1

Bài 44: (SBT/12):

a. (7.3⁵ - 3⁴ + 3⁶) : 3⁴

= (7.3⁵ : 3⁴) + (-3⁴ : 3⁴) + (3⁶ : 3⁴)

= 7 . 3 - 1 + 3²

= 21 - 1 + 9

= 29

b. (16³ - 64²) : 8³

= [(2.8)³ - (8²)² ] : 8³

= (2³ . 8³ - 8⁴) : 8³

= ( 2³ . 8³ : 8³) + (-8⁴ : 8³)

= 2³ - 8

= 8 - 8

= 0

Answer 2

a) \(\left(7.3^5-3^4+3^6\right):3^4\)

\(=7.3^5:3^4-3^4:3^4+3^6:3^4\)

\(=7.3^{5-4}-3^{4-4}+3^{6-4}\)

\(=7.3^1-3^0+3^2\)

\(=7.3-1+9\)

\(=21-1+9\)

\(=20+9\)

\(=29\)

b) \(\left(16^3-64^2\right):8^3\)

\(=\left[\left(2^4\right)^3-\left(2^6\right)^2\right]:\left(2^3\right)^3\)

\(=\left(2^{4.3}-2^{6.3}\right):2^{3.3}\)

\(=\left(2^{12}-2^{12}\right):2^9\)

\(=2^{12-9}-2^{12-9}\)

\(=2^3-2^3\)

\(=8-8\)

\(=0\)