Question

Determinati numerele naturale de forma ab in baza zece,stiind ca suma dintre ab im baza zece si ba tot in baza zece este patrat perfect

Answer 1

Daca ab+ba= patrat perfect
⇒atuci:

10a+b+10b+a=patrat perfect
11*a+11*b=patrat perfect
11*(a+b)=patrat perfect
=> a+b=11
=> ab∈{29,38,47,56,65,74,83,92}