Sagot :
Réponse :
A = 2/9 + 3/72 = (2*8)/(9*8) + 3/72 = 18/72 + 3/72 = 21/72 = (7*3)/(24*3) = 7/24
B = 7/8 - 12/72 = (7*9)/(8*9) - 12/72 = 63/72 - 12/72 = 51/72 = (3*17)/(3*24) = 17/24
C = 7/2 - 67/20 = (7*10)/(2*10) - 67/20 = 70/20 - 67/20 =3/20
D = 3/6 + 17/60 = (3*10)/(6*10) + 17/60 = 30/60 + 17/60 = 47/60
E = 12/9 X 3/36 = 36/324 = (9*4)/(9*36) = 4/36 = (2*2)/(2*18) = 2/18 = (2*1)/(2*9) = 1/9
G = 12/16 X 28/39 = 336/624 = (6*56)/(6*14) = (56/14) = (2*28)/(2*7) = 28/7 = 4
Explications :
A= 2/9+3/72
=8×2/8×9 + 3/72
=16/72 + 3/72
=19/72
B=7/8 - 12/72
=7×9/8×9 - 12/72
=36-12/72
=24/72
=1/3
C=7/2 - 67/20
=7×10/2×10 - 67/60
=70-67/200
=3/20
D=3/6 +7/60
=3×10/6×10 + 7/60
=30+7/60
=37/60
E=12/9 × 3/36
=36/324
=2/9
F=7/8 × 24/40
=168/320
=84/160
=21/40
G=13/10 × 28/30
=364/300
=91/75