Rút gọn các phân số sau -3/21 -9/24 -6/-9 -4/-6 -8/16 45/25 36/24 40/55 -28/46 15/-45 56/70

Đáp án:

 -3/21=-1/7

-9/24= -3/8

-6/-9 = 2/3
-4/-6 = 2/3

-8/16 = -1/2

45/25 = 9/5

36/24 = 3/2

40/55 = 8/11

-28/46= -14/23

15/-45 =-1/3

56/70  = 4/5

$\bullet$ `(-3)/21 = ((-3) : 3)/(21 : 3) = (-1)/7`

$\bullet$ `(-9)/24 = ((-9) : 3)/(24 : 3) = (-3)/8`

$\bullet$ `(-6)/(-9) = 6/9 = (6 : 3)/(9 : 3) = 2/3`

$\bullet$ `(-4)/(-6) = 4/6 = (4 : 2)/(6 : 2) = 2/3`

$\bullet$ `(-8)/16 = ((-8) : 8)/(16 : 8) = (-1)/2`

$\bullet$ `45/25 = (45 : 5)/(25 : 5) = 9/5`

$\bullet$ `36/24 = (36 : 12)/(24 : 12) = 3/2`

$\bullet$ `40/55 = (40 : 5)/(55 : 5) = 8/11`

$\bullet$ `(-28)/46 = ((-28) : 2)/(46 : 2) = (-14)/23`

$\bullet$ `15/(-45) = (-15)/45 = ((-15) : 15)/(45 : 15) = (-1)/3`

$\bullet$ `56/70 = (56 : 14)/(70 : 14) = 4/5`