Câu 2: B

Câu 1: 

H: Đ

I: Đ

h) Đ/i)Đ

câu 2:c

a.1/7,2/3 và 4/21

b.1/2,2/6,1/5

giải giúp mình mình cần gấp!!!

=> 5/6; 4/5; 2/3; 7/12; 1/2

                                1/2    ; 4/5    ; 2/3   ; 5/6     ; 7/12

Khi quy đồng ta có: 30/60; 48/60; 40/60; 50/60; 35/60

\(1,\frac{7}{5},\frac{15}{14},\frac{5}{7},\frac{1}{2},\frac{2}{5}\)

7/ 5 ,   9/8 , 6/ 6  , 1/2

a, ta có 1/2 =5/10;1/3=5/15

4 ps o giua 2 ps do la:

   5/11;5/12;5/13;5/14

1/7;2/3;3/4;9/8;6/5

Ta có:
\(\dfrac{6}{5}=\dfrac{6\times168}{5\times168}=\dfrac{1008}{840}\)     ;    \(\dfrac{3}{4}=\dfrac{3\times210}{4\times210}=\dfrac{630}{840}\)     ;     \(\dfrac{9}{8}=\dfrac{9\times105}{8\times105}=\dfrac{945}{840}\) 

\(\dfrac{1}{7}=\dfrac{1\times120}{7\times120}=\dfrac{120}{840}\)     ;    \(\dfrac{2}{3}=\dfrac{2\times280}{3\times280}=\dfrac{560}{840}\)

⇒ \(\dfrac{120}{840}< \dfrac{560}{840}< \dfrac{630}{840}< \dfrac{945}{840}< \dfrac{1008}{840}\) ⇒ \(\dfrac{1}{7}< \dfrac{2}{3}< \)\(\dfrac{3}{4}< \dfrac{9}{8}< \dfrac{6}{5}\)
 

\(\dfrac{1}{2}=\dfrac{1\cdot24}{2\cdot24}=\dfrac{24}{48}\)

\(\dfrac{3}{48}=\dfrac{3\cdot1}{48\cdot1}=\dfrac{3}{48}\)

\(\dfrac{8}{12}=\dfrac{8\cdot4}{12\cdot4}=\dfrac{32}{48}\)

\(\dfrac{5}{6}=\dfrac{5\cdot8}{6\cdot8}=\dfrac{40}{48}\)

\(\dfrac{7}{12}=\dfrac{7\cdot4}{12\cdot4}=\dfrac{28}{48}\)

mà 3<24<28<32<40

nên \(\dfrac{3}{48}< \dfrac{1}{2}< \dfrac{7}{12}< \dfrac{8}{12}< \dfrac{5}{6}\)

3/48,1/2;7/12;8/12;5/6

3/48, 1/2, 7/12, 8/12, 5/6
hk tốt

1/7 ; 7/7 ; 6/5 ; 5/2

7/7 ; 1/7 ; 6/5; 5/2

a49kg

b,\(\frac{1}{8};\frac{1}{7};\frac{1}{6};\frac{1}{3}\)

c,\(\frac{4}{2};\frac{5}{6};\frac{2}{3}\)