Question

So sánh : A=\(\dfrac{10^8+2}{10^8-1}\);B=\(\dfrac{10^8}{10^8-3}\)
Hurry up now =))) I need an answer =)))

Answer 1

Ta có:A-1=\(\dfrac{10^8+2}{10^8-1}-1=\dfrac{10^8+2-10^8+1}{10^8-1}=\dfrac{3}{10^8-1}\)

B-1=\(\dfrac{10^8}{10^8-3}-1=\dfrac{10^8-10^8+3}{10^8-3}=\dfrac{3}{10^8-3}\)

Do \(\dfrac{3}{10^8-1}>\dfrac{3}{10^8-3}\)

=>A-1>B-1

<=>A>B

Vậy...

Answer 2

mik cũng đg cần

Answer 3

\(A=\dfrac{10^8+2}{10^8-1}=\dfrac{10^8-1+3}{10^8-1}=\dfrac{10^8-1}{10^8-1}+\dfrac{3}{10^8-1}=1+\dfrac{3}{10^8-1}\)

\(B=\dfrac{10^8}{10^8-3}=\dfrac{10^8-3+3}{10^8-3}=\dfrac{10^8-3}{10^8-3}+\dfrac{3}{10^8-3}=1+\dfrac{3}{10^8-3}\)

Vì \(\dfrac{3}{10^8-1}< \dfrac{3}{10^8-3}\)

Nên \(1+\dfrac{3}{10^8-1}< 1+\dfrac{3}{10^8-3}\)

Vậy A < B.