Réponses

2014-03-19T14:56:59+01:00
C= (7+3z)(2z+3).
=7 x 2z + 7x 3 + 3z x 2z + 3z x 3
= 14z+ 21+ 6z+ 9z
= 29z+ 21
D= (10+8t)(9+2t).
= 10 x 9 + 10 x 2t + 8t x 9 + 8t x 2t
= 90 + 20t + 72t + 16t
90 + t ( 20+72+16)
90+108t