Question

So sánh:  A=  2015^20 / 2015^20-6.         B = 2015^20+4 /  2015^20-2

Answer 1

\(A=\frac{2015^{20}-6+6}{2015^{20}-6}=\frac{2015^{20}-6}{2015^{20}-6}+\frac{6}{2015^{20}-6}=1+\frac{6}{2015^{20}-6}\)

\(B=\frac{2015^{20}-2+6}{2015^{20}-2}=\frac{2015^{20}-2}{2015^{20}-2}+\frac{6}{2015^{20}-2}=1+\frac{6}{2015^{20}-2}\)

Vì \(2015^{20}-6\frac{6}{2015^{20}-2}\)

=> A > B