Question

Tìm x

7x- 2x= 5⁶⁹-5⁶⁷

Answer 1

7x - 2x = 5⁶⁹ - 5⁶⁷

=> 5x = 5⁶⁷.(5² - 1)

=> 5x = 5⁶⁷ . 24

=>   x = 5⁶⁷ . 24 : 5

=>   x = 5⁶⁶ . 24

Vậy x = 5⁶⁶ . 24 

Answer 2

7x-2x=5⁶⁹-5⁶⁷

=> (7x - 2x ) -( 5⁶⁹ - 5⁶⁷⁾ =0

Mik chỉ giúp đc ý này thôi

Answer 3

\(7x-2x=5^{69}-5^{67}\)

\(5x=5^{67}\left(5^2-1\right)\)

\(\Rightarrow x=5^{66}\left(5^2-1\right)\)

\(x=5^{66}.24\)

Vậy...