Question

care sunt numerele de forma xyz stiind ca xy+yz+zx=66 ?

Answer 1

xy+yz+zx=66

10x+y+10y+z+10z+x=66

11x+11y+11z=66     /:11

x+y+z=6

=> x+y+z=1+1+4=1+2+3=1+3+2=1+4+1=2+1+3=2+2+2=2+3+1=3+1+2=3+2+1=4+1+1

xyz={114; 123; 132; 141; 213; 222; 231; 312; 321; 411}