Question

So sánh các số sau:

\(72^{45}-72^{43}\) và \(72^{44}-72^{43}\)

Answer 1

\(72^{45}>72^{44}\)

\(\Rightarrow72^{45}-72^{43}>72^{44}-72^{43}\)

Vậy...

Answer 2

Dễ quá:

Do \(72^{45}>72^{44}=>72^{45}-72^{43}>72^{44}-72^{43}\)

Answer 3

Ta có:

+) \(72^{45}-72^{43}=\left(72^2-1\right)\cdot72^{43}\)

+) \(72^{44}-72^{43}=\left(72-1\right)\cdot72^{43}\)

Mà \(72^2>72\)

do đó: \(\left(72^2-1\right)\cdot72^{43}>\left(72-1\right)\cdot72^{43}\)

Suy ra: \(72^{45}-72^{43}>72^{44}-72^{43}\)