bằng 1000 nha bn

k mk nha bn

thanks

519 + 481 = 1000

\(519+481\)

\(=\)\(1000\)

=( 5² - 4 ) : 7 

=( 25 - 4 ) : 7 

= 21 : 7 

=3

= (5² - 4) : 7

= 21 : 7

= 3

\(\left(5^{19}:5^{17}+3\right):7\)

\(=\left(5^2+3\right):7\)

\(=\left(25+3\right):7\)

\(=28:7\)

\(=4\)

=>6x=30

hay x=5

7x - x = 30
7.x - 1.x = 30
x . (7-1) = 30
x . 6 = 30

x      = 30 : 6
x      = 5

DỄ ƠI LÀ DỄ

\(7x-x=5^{21}:5^{19}+3.2^2-7^0\)

\(6x=5^2+3.2-1\)

\(6x=25+12-1\)

\(6x=36\)

\(x=6\)

K bt đk:))
Ta có :
7x - x = 5²¹ : 5¹⁹ . 3 . 2² - 70

=> 6x = 5²¹: 5¹⁹ + 3 . 2² - 70

=> 6x = 5² + 3. 4 - 1

=> 6x = 25 + 3 . 2 - 1

=> 6x = 25 + 6 - 1

=> 6x = 30

=> x = 30 : 6

=> x = 5

7x−x=521:519+3.22−70

6x=52+3.2−16x=52+3.2−1

6x=25+12−16x=25+12−1

6x=366x=36

x=6

x = 52.(2)

 (83 + 519) . x = 66 . 100 + 22

 (83 + 519) . x = 6600 + 22

 (83 + 519) . x = 6622

            602 . x = 6622

                      x = 6622 : 602

                      x = 11

x= 11 à rồng 3 đầu

- 5 19 + 3 19 < x 19 ≤ 13 19 + - 11 19 ⇔ - 2 19 < x 19 ≤ 2 19 - 2 < x ≤ 2

Mà x thuộc Z

Do đó  x ∈ - 1 ; 0 ; 1 ; 2

c) (5^{19 - 17} + 3) : 7

= (5² + 3) : 7

= (25 + 3) : 7

= 28 : 7

= 4