Réponses

2012-09-19T18:20:35+02:00

a) 1,5+(-5)x2,5+(-5,5)x(-2)

=1.5-12,5+11

= 11-11

=0 

 

b) (13-2,5)x(3-10)+(-5)x(-18)

=10,5x(-7)+90

=-73,5+90

=16.5

 

Voila .