1. The problem statement, all variables and given/known data Given are two integers a and b: a has 2 digits and b has 4 digits. All digits are smaller than 9. a and b are such that [itex] a^2 = b [/itex]. If all digits are raised by one this is still valid. What are a and b? 2. Relevant equations N/a 3. The attempt at a solution Suppose [itex] a = a_0 \cdot 10^0 + a_1 \cdot 10^1 [/itex] and [itex] b = b_0 \cdot 10^0 + b_1 \cdot 10^1 + b_2 \cdot 10^2 + b_3 \cdot 10^3 [/itex] then it gets messy if I use [itex] a^2 = b [/itex] and if I increase all digits by one. I think should get two equations with 2 unknowns.