Bonsoir pouvez vous m’aider a faire la 29 ,30 et 31 svp je n’est pas compris

29)

-2/7 x 14/16 = (-2 x 14)/(7 * 16) = (-2 x 2 x 7)/(7 x 2 x 2 x 4) = -1/4

-3/5 x -15/7 = (-3 x -15)/(5 x 7) = (3 x 3 x 5)/(7 x 5 ) = 9/7

-4/3 x 3/5 = (-4 x 3)/(3 x 5) = -4/5

30)

-1/5 x 5/-3 = (-1 x 5)/(-5 x 3) = 1/3

-3/5 x 7/9 = (-3 x 7)/(5 x9) = (-3 x 7)/(5 x 3 x 3) = -7/(5 x3) = -7/15

-5/-4 x 2/15 = 5/4 x 2/15 = (5 x 2)/(4 * 15) = (5 x 2)/(2 x 2 x 5 x 3) = 1/(2 x 3) = 1/6

31)

6/5 x 11/4 = (6 x 11)/(5 x 4) = (3 x 2 x 11)/(5 x 2 x 2) = (3 x 11)/(5 x 2) = 33/10

-9/5 x 7/6 = (-9 x 7)/(5 x 6) = (-3 x 3 x 7)/(5 x 3 x 2) = (-3 x 7)/(5 x 2) = -21/10

-10/9 x -7/15 = (-10 x -7)/(9 x 15)= (10 x 7)/(9 x 15) = (5 x 2 x 7)/(9 x 3 x 5) = (2 x 7)/(9 x 3) = 14/27