Question

tính\(\left[\left\{3^{14}.69+3^{14}.12\right\}:3^{16}-7\right]:2^4\)

Answer 1

\(\left\{\left[3^{14}.69+3^{14}.12\right]:3^{16}-7\right\}:2^4\\ =\left[3^{14}\left(69+12\right):3^{16}-7\right]:2^4=\left[\left(3^{14}.3^4\right):3^{16}-7\right]:2^4\\ =\left(3^2-7\right):2^4=\left(9-7\right):2^4=2:2^4=\dfrac{1}{8}\)

Answer 2

Bạn ơi! Bạn viết sai dấu ngoặc nhé! Mình sửa thành:

[(3¹⁴. 69 + 3¹⁴. 12) : 3¹⁶ - 7] : 2⁴

= {[ 3¹⁴. (69 + 12)] : 3¹⁶ - 7} : 2⁴

= {[ 3¹⁴. 81] : 3¹⁶ - 7} : 2⁴

= {[3¹⁴. 3⁴] : 3¹⁶ - 7} : 2⁴

= {3¹⁸ : 3¹⁶ - 7} : 2⁴

= {3² - 7} : 2⁴

= {9 - 7} : 2⁴

= 2 : 16

= \(\dfrac{1}{8}\)

= 8.