a) dam factor 2 si obtinem in paranteza y+z; inlocuim
3x + 2(y+z)
3*23 + 2*41 = 69+82 = 151
b) 5x + 3(y+z) = 5*23 + 3*41 = 115 + 123 = 238
d) 4(y+z) -5x = 4*41-5*23 = 164-115 = 49
e) 7(y+z) -9x = 7*41-9*23 = 287-207 = 80
