Question

Va rog urgent: 
1. Aflati a, daca b+c=5 si ab+ac+7a=96
2. Daca n>3,comparati a=n+6 si b=3n

Answer 1

1. b+c= 5
ab+ac+7a= 96

a=? 

ab+ac+7a= a(b+c+7)= 96
⇒ a(5+7) = 96
⇒ a= 96:(5+7)
⇒a= 96: 12
⇒a= 8.

2.  n>3

a= n+6
b= 3n.

prin incercari ca n= 4 (a= 10, b= 12), n= 9 ( a= 15, b= 27), n= 20 ( a= 26, b= 60....) constatam ca indiferent de valoarea lui n>3, a<b