\(b=4022k+1234\left(k\in N\right)\)
hoặc \(b=6033t+1234\left(t\in N\right)\)
\(\Rightarrow4022k+1234=6033t+1234\)
\(\Rightarrow2k=3t\)
mà \(t\in N\) nên đặt t = 2m \(\left(m\in N\right)\)
\(\Rightarrow b=12066m+1234\)
\(\Rightarrow80000< 12066m+1234< 90000\)
\(\Rightarrow78766< 12066m< 88766\)
\(\Rightarrow m=7\)
\(\Rightarrow b=85696\)