a)\(\left(5^{23}.5^{18}\right):5^{39}-5^0.0^5\)

= \(5^{41}:5^{39}-1.0\)

= \(5^2-0\)

= \(25-0=25\)

b)\(\left[2.3^3+144:\left(7^2-925:5^2\right)\right].\left|-8\right|\)

= \(\left[2.27+144:\left(49-925:25\right)\right].8\)

= \(\left[54+144:\left(49-37\right)\right].8\)

= \(\left[54+144:12\right].8\)

= \(\left[54+12\right].8\)

= \(66.8\)

= 528

Sửa đề: \(5^9\cdot49^2\)

\(=\dfrac{5^{10}\cdot7^3-5^9\cdot7^4}{5^9\cdot7^3+5^9\cdot14^3}-\dfrac{2^{12}-2^{12}\cdot3^4}{2^{12}\cdot3^6+2^{12}\cdot3^5}\)

\(=\dfrac{5^9\cdot7^3\left(5-7\right)}{5^9\cdot7^3\left(1+8\right)}-\dfrac{2^{12}\left(1-3^4\right)}{2^{12}\left(3^6+3^5\right)}=\dfrac{-2}{9}+\dfrac{80}{972}\)

=-34/243

a) 3³ + 3² - ( 2⁷ : 2⁵ + 7⁸ : 7⁷ )

= 27 + 9 - ( 2² + 7 )

= 36 - 11

= 25

b) 27 . 77 + 27 . 27 - 27

= 27 . 77 + 27 . 27 - 27 . 1

= 27( 77 + 27 - 1 )

= 27 . 103

= 2781

c) 52 : ( 43 - 30 ) + 144 - 16

= 52 : 13 + 144 - 16

= 4 + 144 - 12

= 136

{ 2 . 3² + [ 144 - 5² . ( 15 - 169 : 13 ) ] } - 1²⁰¹⁹

= { 2 . 9 + [ 144 - 25 . ( 15 - 13 ) ] } - 1

= { 18 + [ 144 - 25 . 2 ] } - 1

= { 18 + [ 144 - 50 ] } - 1

= 18 + 94 - 1

= 112 - 1

= 111

{2 . 3^2 + (144 - 5^2 . (15 - 169 : 13))} - 1^2019

= {2 . 9 + (144 - 25 . ( 15 - 169 : 13))} - 1

= {2 . 9 + (144 - 25 . ( 15 - 13))} - 1

= {2 . 9 + (144 - 25 . 2)} - 1

= {2 . 9 + (144 - 50)} - 1

= {2 . 9 + 94} - 1

= {18 + 94} - 1

= 112 - 1

= 111

Đề bài yêu cầu gì?

a)

160 : (4 × 8) = 160 : 32 = 5

160 : 4 : 8 = 40 : 8 = 5

Vậy 160 : (4 × 8) = 160 : 4 : 8.

96 : (3 × 8) = 96 : 24 = 4

96 : 3 : 8 = 32 : 8 = 4

Vậy 96 : (3 × 8) = 96 : 3 : 8.

105 : (5 × 7) = 105 : 35 = 3

105 : 5 : 7 = 21 : 7 = 3

Vậy 105 : (5 × 7) = 105 : 5 : 7.

Nhận xét: a : (b × c) = a : b : c

b)

270 : (9 × 6) = 270 : 9 : 6 = 30 : 6 = 5

420 : (7 × 3) = 420 : 7 : 3 = 60 : 3 = 20

144 : (2 × 8) = 144 : 2 : 8 = 72 : 8 = 9

\(A=\dfrac{2^{12}\cdot3^5-2^{12}\cdot3^4}{2^{12}\cdot3^6+2^{12}\cdot3^5}-\dfrac{5^{10}\cdot7^3-5^{10}\cdot7^4}{5^9\cdot7^3+5^9\cdot7^3\cdot2^3}\)

\(=\dfrac{3^4\left(3-1\right)}{3^5\left(3+1\right)}-\dfrac{5^{10}\cdot7^3\left(1-7\right)}{5^9\cdot7^3\cdot9}\)

\(=\dfrac{1}{3\cdot2}-\dfrac{1}{5}\cdot\dfrac{-6}{9}=\dfrac{1}{6}+\dfrac{6}{45}=\dfrac{45+36}{270}=\dfrac{81}{270}=\dfrac{3}{10}\)

1.  25 : 5,7 = 250/57

2.  30:2.8.4 = 480

3.  20:2^2.14= 70

4.  125:5^3.170= 170

5.  64:2^5.30.4=240

6.  (25:5^2.30): 15.7=14

       bạn à! Nhiều quá mình ko làm hết được. sorry nha.^-^                     

dù dài quá nhưng cố  gắng giúp mình làm hết nha