Explications étape par étape:

B: je commence par simplifier le haut.

1 + 3/2 = 2/2 + 3/2 = 5/2

on a donc (5/2 ÷ 3) -2/3 = (5/2 - 2)/3 = (5/2 - 4/2)/3 =

1/2 ÷ 3 = 1/2 × 1/3 = 1/6.

je simplifie le bas:

1 + 2/3 = 3/3 + 2/3 = 5/3

2÷ 5/3 = 2 × 3/5 = 6/5

on a donc 1/2 - 6/5 = 5/10 - 12/10 = -2/10 = -1/5

B = 1/6 ÷ (-1/5) = 1/6 × (-5/1) = -5/6