Bonjour
Calculer et mettre sous forme irréductible, en détaillant, les expressions suivantes :
A = 2/5 + 3/4 x 7/15
A = (2 x 12) / (5 x 12) + 21/60
A = 24/60 + 21/60
A = 45/60
A = (15 x 3) / (15 x 4)
A = 3/4
B = (2/3)² + 1/5 x 4/3
B = 4/9 + 4/15
B = (4 x 5) / (9 x 5) + (4 x 3) / (15 x 3)
B = 20/45 + 12/45
B = 32/45
C = (2/3 - 1/2) / (5/4 - 4/5)
C = [(2 x 2) / (3 x 2) - (1 x 3) / (2 x 3)] / [(5x 5) / (4 x 5) - (4 x 4) / (5 x 4)]
C = (4/6 - 3/6) / (25/20 - 16/20)
C = 1/6 : 9/20
C = 1/6 x 20/9
C = 20/54
C = (2 x 10) / (2 x 27)
C = 10/27
D = 5/3 : 3/4 + 7/8
D = 5/3 x 4/3 + 7/8
D = 20/9 + 7/8
D = (20 x 8) / (9 x 8) + (7 x 9) / (8 x 9)
D = 160/72 + 63/72
D = 223/72.
