K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

Ta có \(B=\frac{2015+2016+2017}{2016+2017+2018}\)

\(\Leftrightarrow B=\frac{2015}{2016+2017+2018}+\frac{2016}{2016+2017+2018}+\frac{2017}{2016+2017+2018}\)


\(\frac{2015}{2016}>\frac{2015}{2016+2017+2018};\frac{2016}{2017}>\frac{2016}{2016+2017+2018};\frac{2017}{2018}>\frac{2017}{2016+2017+2018}\) nên \(\frac{2015}{2016}+\frac{2016}{2017}+\frac{2017}{2018}>\frac{2015}{2016+2017+2018}+\frac{2016}{2016+2017+2018}+\frac{2017}{2016+2017+2018}\)

Hay \(A>B\)

26 tháng 4 2016

\(A=\frac{2015+2016}{2016+2017}=\frac{2015}{2016+2017}+\frac{2016}{2016+2017}\)

\(B=\frac{2015}{2016}+\frac{2016}{2017}\)

vì \(\frac{2015}{2016+2017}<\frac{2015}{2016}\)và \(\frac{2016}{2016+2017}<\frac{2016}{2017}\)

nên A <B

23 tháng 6 2016

A = 2016 x 2016

A = (2015 + 1) x 2016

A = 2015 x 2016 + 2016

B = 2015 x 2017

B = 2015 x (2016 + 1)

B = 2015 x 2016 + 2015

Vì 2016 > 2015

=> A > B

23 tháng 6 2016

A = \(2016^2\)

B = \(\left(2016-1\right)\left(2016+1\right)=2016\left(2016+1\right)-\left(2016+1\right)\)\(2016^2+2016-2016-1\)\(2016^2-1\)

\(\Rightarrow A>B\). Vậy A > B

26 tháng 4 2018

\(Q=\frac{2015+2016+2017}{2016+2017+2018}=\frac{2015}{2016+2017+2018}+\frac{2016}{2016+2017+2018}+\)\(\frac{2017}{2016+2017+2018}\)

ta có :

\(\frac{2015}{2016}>\frac{2015}{2016+2017+2018}\)

\(\frac{2016}{2017}>\frac{2016}{2016+2017+2018}\)

\(\frac{2017}{2018}>\frac{2017}{2016+2017+2018}\)

nên \(P>Q\)

26 tháng 4 2018

Q=2015+2016+2017/2016+2017+2018=+2018+2016/2016+2017+2018+2017/2016+2017+2018
vì 2015/2016>2015/2016+2017+2018[1]
2016/2017>2016+2017+2018[2]
2017/2018>2016+2017+2018[3]
từ [1] [2] [3] suy ra P>Q

29 tháng 4 2016

Bạn quy đồng b rồi ra luôn

29 tháng 4 2016

Ta thấy : 
 \(\frac{2014}{2016}>\frac{2014}{2016+2017}\) 
 \(\frac{2015}{2017}>\frac{2015}{2016+2017}\)
\(\Rightarrow\frac{2014}{2106}+\frac{2015}{2017}>\frac{2014}{2016+2017}+\frac{2015}{2016+2017}=\frac{2014+2015}{2016+2017}\)
=> B>A