qui pour m’aider s’il vous plaît exercice 2

A = 1/3 - 1/3 × 4/7

A = 1/3 - 4/21

A = 1×7/3×7 - 4/21

A = 7/21 - 4/21

A = 3/21

A = 1×3/3×7

A = 1/7

B = 6/5 + (1/15 - 1/5)

B = 6/5 + (1/15 - 1×3/5×3)

B = 6/5 + (1/15 - 3/15)

B = 6/5 + (-2/15)

B = 6×3/5×3 - 2/15

B = 18/15 - 2/15

B = 16/15

B = 1,06...