FACTORISE LES SOMMES
C = 3 x u - 3 x v + 3 x 9
D = 13 x a - 8 x 2 x b + (12+ 4) x c
DEVELOPPE LES PRODUITS SUIVANTS
7 x (a + x -3) ;
(3 + t ) x 9;
12 x (x-y-z)
C=3(u-v+9)
D=16(13a/16 -b +c)
7 x (a + x -3) =7a+7x-21
(3 + t ) x 9=27+9t
12 x (x-y-z)=12x-12y-12z