Bonsoir,
Calculer
B=4/5+2/15
B = (4 x 3) / (5 x 3) + 2/15
B = 12/15 + 2/15
B = 14/15
E= 8/9-1/3
E = 8/9 - (1 x 3) / (3 x 3)
E = 8/9 - 3/9
E = 5/9
F=3-5/7
F = (3 x 7) / (1 x 7) - 5/7
F = 21/7 - 5/7
F = 16/7
G=13/12-19/48
G = (13 x 4) / (12 x 4) - 19/48
G = 42/48 - 19/48
G = 23/48
H= 17/13-11/65
H = (17 x 5) / (13 x 5) - 11/65
H = 85/65 - 11/65
H = 74/65
Simplifie une des deux fractions avant d'effectuer le calcul :
A=8/12+5/3
A = 8/12 + (5 x 4) / (3 x 4)
A = 8/12 + 20/12
A = 28/12
A = (4 x 7) / (4 x 3)
A = 7/3
B=40/72-1/9
B = 40/72 - (1 x 8) / (9 x 8)
B = 40/72 - 8/72
B = 32/72
B = (8 x 4) / (8 x 9)
B = 4/9
C=15/35+2/7
C = 15/35 - (2 x 5) / (7 x 5)
C = 15/35 - 10/35
C = 5/35
C = (5 x 1) / (5 x 7)
C = 1/7.
D=5/3-52/39
D= (5 x 13) / (3 x 13) - 52/39
D = 65/39 - 52/39
D = 13/39
D = (13 x 1) / (13 x 3)
D = 1/3.