5^n+2-5^n=600. Cine ma poate ajuta?

Răspuns :

[tex]5^{n+2}-5^n=600\\5^n(5^2-1)=600\\5^n\cdot 24=600\\5^n=25\\5^n=5^2\\\boxed{n=2}[/tex]

5ⁿ⁺² - 5ⁿ = 600

5ⁿ x ( 5² - 1 ) = 600

5ⁿ x 24 = 600

5ⁿ = 600 : 24

5ⁿ = 25

5ⁿ = 5²  ⇒   n = 2