a) 2^n+3*2^n+1+5*2^n+2=2^n+3*2*2^n+5*2*2*2^n=2^n(1+6+20)=2^n*27=2^n-1*54 care se divide cu 54
b)9^n+2+5*9^n=9^n*9^2+5*9^n=9^n(81+5)=9^n*86 care se divide cu 86
c)2^n+3*2^n+1+5*2^n+2= 2^n(1+3*2+5*4)=2^n*27 care se divide cu 27( este aceeasi ecuatie ca la punctul a).