Question

Nu-mi dau seama, cum sa efectuez exercitiul.
Determinati numarul natural x.

Answer 1

3^x(1 + 3 + 3^2) = 3159 
3^x * 13 = 3159 
3^x = 3159 : 13
3^x = 243 
3^x = 3^5 
x = 5 

Answer 2

$3^{x}+3^{x+1}+3^{x+2}=3159$

$3^{x}+3^{x}*3^{1}+3^{x}*3^{2}=3159$

$3^{x}(1+3^{1}+3^{2})=3159$

$3^{x}(1+3+9)=3159$

$3^{x}*13=3159$

$3^{x}=3159:13$

$3^{x}=243$

$3^{x}=3^{5}$

$=> \boxed{x=5}$