bonjour

1. a = - 7 et b = - 11

- 7 - ( - 11 )= - 7 + 11 = 4

4 : 2 = 2

2 - 11 = - 9

a = - 1 et  b = 2

2 - ( - 1 )  = 2 + 1 = 3

3 : 2 = 1.5

1.5 + ( - 1 ) = 1.5 - 1 = 0.5

permet de claculer la distance entre  2 points