Question

[hoa 4 tâm tứ đóa hoa]

so sanh
a )
\(\frac{179}{197}va\frac{971}{917}\)
 b )
\(\frac{64}{85}va\frac{73}{81}\)

c )
\(\frac{456}{461}va\frac{123}{128}\)
d )
\(\frac{53}{57}va\frac{531}{571}\)
e )
\(\frac{58}{89}va\frac{36}{53}\)
g )
\(\frac{11}{32}va\frac{16}{49}\)


 

Answer 1

[Trà My]

a) Ta có: \(\frac{179}{197}< 1\)và \(\frac{971}{917}>1\)

\(\Rightarrow\frac{179}{197}< 1< \frac{971}{917}\)

\(\Rightarrow\frac{179}{197}< \frac{971}{917}\)

b)Ta có: \(\frac{64}{85}< \frac{64}{81}\) mà \(\frac{73}{81}>\frac{64}{81}\)

\(\Rightarrow\frac{64}{85}< \frac{64}{81}< \frac{73}{81}\)

\(\Rightarrow\frac{64}{85}< \frac{73}{81}\)

Tự làm tiếp nha ~

Answer 2

[soyeon_Tiểu bàng giải]

a) Vì 179/197 < 1 ; 971/917 > 1

=> 179/197 < 971/917

b) Vì 64/85 < 64/81 < 73/81

=> 64/85 < 73/81

c) Ta có: 456/461 = 1 - 5/461 ; 123/128 = 1 - 5/128

Vì 5/461 < 5/128 => 1 - 5/461 > 1 - 5/128

=> 456/461 > 123/128

d) 53/57 = 530/570

Áp dụng a/b < 1 => a/b < a+m/b+m (a,b,m thuộc N*)

Do 530/570 < 1 => 530/570 < 530+1/570+1

=> 53/57 < 531/571

e) Ta có: 58/89 > 58/87 = 2/3

36/53 < 36/54 = 2/3

=> 58/89 > 36/53

g) Ta có: 11/32 > 11/33 = 1/3

16/49 < 16/48 = 1/3

=> 11/32 > 16/49