Question

Cho A = \(\dfrac{2017}{2018}+\dfrac{2018}{2019}\)

B = \(\dfrac{2017+2018}{2018+2019}\)

So sánh A và B

Answer 1

Ta có: \(\dfrac{2017}{2018}>\dfrac{2017}{2018+2019}\)

\(\dfrac{2018}{2019}>\dfrac{2018}{2018+2019}\)

=> \(\dfrac{2017}{2018}+\dfrac{2018}{2019}>\dfrac{2017+2018}{2018+2019}\)

=> A > B

Answer 2

Ta có :

\(B=\dfrac{2017+2018}{2018+2019}=\dfrac{2017}{2018+2019}+\dfrac{2018}{2018+2019}\)

Ta thấy :

\(\dfrac{2017}{2018}>\dfrac{2017}{2018+2019}\left(1\right)\)

\(\dfrac{2018}{2019}>\dfrac{2018}{2018+2019}\left(2\right)\)

Từ \(\left(1\right)+\left(2\right)\Leftrightarrow A>B\)

Answer 3

Ta có:

\(\dfrac{2017}{2018}>\dfrac{2017}{2018+2019}\) (1)

\(\dfrac{2018}{2019}>\dfrac{2018}{2016+2019}\) (2)

Từ (1) và (2)⇒ A> B

Answer 4

Ta có:

\(\dfrac{2017}{2018}\) > \(\dfrac{2017}{2018+2019}\)

\(\dfrac{2018}{2019}\) > \(\dfrac{2018}{2018+2019}\)

⇒ \(\dfrac{2017}{2018}\) + \(\dfrac{2018}{2019}\) > \(\dfrac{2017+2018}{2018+2019}\)

( Chúc Bạn Học Tốt)