Question

Determinati numerele naturale de forma abc,stiind ca a + c =6xb

Answer 1

b=1
a+c=6    
deci a={1,2,3,4,5,6}   si  c={0,1,2,3,4,5}
numerele fiind 115,214,313,412,511,610       = 6 nr

b=2 
a+c=12    
deci a={3,4,5,6,7,8,9}   si  c={3,4,5,6,7,8,9}
numerele fiind 329,428,527,626,725,824,923  = 7 nr
 
 b=3
 a+b=18
 deci a=9  si c=9
deci nr este 939    =  1 nr

6+7+1=14 nr de forma abc