a. daca n =0 ,1,2,3,4 adevarat
3⁰ =1 3¹=3 3²=9 3³ =27 3⁴ = 81 < 95
b 14 < 2 ( la n ) < 129
daca n = 4,5,6, 7 2⁴=16 2⁵=32 2⁶=64 2⁷=128
c. 3( la n -1) < 57 daca n = 0 , 1,2,3, 4
57 < 3 ( la n +2 ) daca n =2 , 3 , 4 , 5 , 6 ,.....
solutia = n comun este n = 2 , 3 , 4
d 7 ( la n - 2 ) ≤ 343 343 = 7³
n= 0 ,1,2 ,3 ,4, 5 din n -2 ≤ 3 ; n ≤ 5
