Réponses

2012-04-24T18:53:31+02:00

A = x - 1 -y + 2 = x - y +1 = -2 + 1 = -1

 

B= x- (1-y) -2 = x - 1 + y - 2 = x + y - 3 = 3 - 3 = 0

 

C= (x-1) - (y-2) = x - 1 - y + 2 = x - y + 1 = -2 + 1 = -1

 

D= x- (-1-y) -2 = x + 1 + y - 2 = x + y -1 = 3 - 1 = 2