Salut !
1 ÷ (1 - 1 ÷ (1 - 1/2))
= 1 ÷ (1 - 1 ÷ 1/2)
= 1 ÷ (1 - 2)
= 1 ÷ (-1)
= -1
1 ÷ (1 - (1 - (1 - (1 - 1/6))))
= 1 ÷ (1 - (1 - (1 - 5/6)
= 1 ÷ (1 - (1 - 1/6)
= 1 ÷ (1 - 5/6)
= 1 ÷ 1/6
= 6
