Exo 2 : Calculer sous forme de fraction irréductible
A=1/2+3/4
A = 1 x 2 / 2 x 2 + 3/4
A = 2/4 + 3/4
A = 5/4
B=5/6×12/25
B = 5 x 12 / 6 x 25
B = 60/150
B = 30 x 2 / 30 x 5
B = 2/5
C=4/7:12/14
C = 4/7 x 14/12
C = 4 x 14 / 7 x 12
C = 56/84
C = 28 x 2 / 28 x 3
C = 2/3
D=(3/2-1/3)×2/5
D = (3 x 3 / 2 x 3 - 1 x 2 / 3 x 2) x 2/5
D = (9/6 - 2/6) x 2/5
D = 7/6 x 2/5
D = 7 x 2 / 6 x 5
D = 14/30
D = 2 x 7 / 2 x 15
D = 7/15
E=1/2+25/4×2/5
E = 1/2 + 25 x 2 / 4 x 5
E = 1/2 + 50/20
E = 1 x 10 / 2 x 10 + 50/20
E = 10/20 + 50/20
E = 60/20
E = 20 x 3 / 20 x 1
E = 3/1
E = 3