![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Quy đồng 2 phân số về dạng mẫu số chung . Ta có :
\(\frac{-64}{85}=\frac{-64.81}{85.81}=\frac{-5184}{6885}\)
\(\frac{-73}{81}=\frac{-73.85}{81.85}=\frac{-6205}{6885}\)
Ta thấy : (-5184) > (-6205) \(\left(\frac{-5184}{6885}>\frac{-6205}{6885}\right)\)
Vậy \(\frac{-64}{85}>\frac{-73}{81}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a)
\(\frac{64}{85}< \frac{64}{81}< \frac{73}{81}\)
=>\(\frac{64}{85}< \frac{73}{81}\)
b)
\(\frac{25}{26}=\frac{25.1010}{26.1010}=\frac{25250}{26260}\)
Ta có: \(1-\frac{25250}{26260}=\frac{1010}{26260}\)
\(1-\frac{25251}{26261}=\frac{1010}{26261}\)
Vì \(\frac{1010}{26260}>\frac{1010}{26261}\) nên \(\frac{25}{26}< \frac{25251}{26261}\)
a)\(\frac{64}{85}\)<\(\frac{64}{81}\)<\(\frac{73}{81}\)
b)\(\frac{25}{26}\)=\(\frac{25250}{26260}\)=\(1\)- \(\frac{1010}{26260}\)< \(1\)- \(\frac{1010}{26261}\)= \(\frac{25251}{26261}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có : \(\frac{64}{85}< \frac{64}{81}\)mà \(\frac{73}{81}>\frac{64}{81}\)
=> \(\frac{64}{85}< \frac{64}{81}< \frac{73}{81}\)
=> \(\frac{64}{85}< \frac{73}{81}\)
\(\frac{n+1}{n+2}>\frac{n+1}{n+3}>\frac{n}{n+3}\)
\(\frac{n+1}{n+2}>\frac{n}{n+3}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(\dfrac{43}{47}=\dfrac{47-4}{47}=\dfrac{47}{47}-\dfrac{4}{47}=1-\dfrac{4}{47}\)
\(\dfrac{53}{57}=\dfrac{57-4}{57}=\dfrac{57}{57}-\dfrac{4}{57}=1-\dfrac{4}{57}\)
Vì \(\dfrac{4}{47}>\dfrac{4}{57}\)=>\(1-\dfrac{4}{47}< 1-\dfrac{4}{57}\)
=>\(\dfrac{43}{47}< \dfrac{53}{57}\)
b) Ta chọn phân số trung gian là: \(\dfrac{64}{81}\)
Vì \(\dfrac{64}{81}>\dfrac{64}{85}\)
Mà \(\dfrac{64}{81}< \dfrac{73}{81}\)
=> \(\dfrac{64}{85}< \dfrac{64}{81}< \dfrac{73}{81}\)
Vậy \(\dfrac{64}{85}< \dfrac{73}{81}\)
c) Ta chọn phân số trung gian là: \(\dfrac{18}{37}\)
Vì \(\dfrac{18}{37}>\dfrac{15}{37}\)
Mà \(\dfrac{18}{37}< \dfrac{18}{31}\)
=> \(\dfrac{15}{37}< \dfrac{18}{37}< \dfrac{18}{31}\)
Vậy \(\dfrac{18}{31}>\dfrac{15}{37}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
>>>>>>>>>>>>>>..
Chọn phân số 73/94 làm phân số trung gian
Ta có: 64/85=1-21/85<73/94=1-21/94 (vì 21/85>21/94 )
Mà 73/94 <73/81
=> 64/85 <73/81 => -64/85>-73/81
Vậy A>B