According to the meaning of the question, the British mathematician De? Morgan is X years old in x2, that is, the square of his age should be18×××× year.
422= 1764, which does not meet the meaning of the question;
432= 1849, in line with the meaning of the question;
That is, when he was 43 years old, he was 1849, so his birth year was1849-43 =1806;