a) 10x+y+10y+z+10z+x=77
11x+11y+11z=77
x+y+z=7
cum x,y,z sunt cifre distincte si nenule, exista mai multe solutii:
×=1, y=2, z=4 deci xyz=124
×=1, y=4, z=2 deci xyz=142
x=2, y=1, z=4 deci xyz=214
x=2, y=4, z=1 deci xyz=241
x=4, y=1, z=2 deci xyz=412
x=4, y=2, z=1 deci xyz= 421
b) 8^n+8^n+1=18*2^2015
2^3n(1+8)=18*2^2015
2^3n=2^2016
3n=2016
n=672