Effectuer les calculs suivants et donner les résultats sous forme de fractions irréductibles: A= 3/2 - 1/5 x 25/7 B= ( 2/8 - 3/5 ) / 3/10

Bonjour,

A= 3/2 - 1/5 x 25/7
A = 3/2 - 25/35
A = 3 x 35 / 2 x 35 - 25 x 2 / 35 x 2
A = 105/70 - 50/70
A = 55/70
A = 5 x 11 / 5 x 14
A = 11/14

B= ( 2/8 - 3/5 ) / 3/10
B = (2 x 5 / 8 x 5 - 3 x 8 / 5 x 8) : 3/10
B = (10/40 - 24/40) : 3/10
B = - 14/40 x 10/3
B = - 140/120
B = 20 x - 7 / 20 x 6
B = - 7/6

C= 2 - ( 3 - 1/3 ) / ( 3 + 1/3 )
C = 2 - (3 x 3 / 1 x 3 - 1/3) : (3 x 3 / 1 x 3 + 1/3)
C = 2 - (9/3 - 1/3) : (9/3 + 1/3)
C = 2 - 8/3 : 10/3
C = 2 - 8/3 x 3/10
C = 2 - 24/30
C = 2 x 30 / 1 x 30 - 24/30
C = 60/30 - 24/30
C = 36/30
C = 6 x 6 / 6 x 5
C = 6/5