(A) sum of two squares of two odd integers cannot be a perfect square
(B) the product of four consecutive integers is $1$ less than a perfect square
For (A) I let the two odd integers be $2a + 1$ and $2b + 1$ for any integers $a$ and $b$. After completing the expansion for sum of their squares , I could not establish the link to it not being a perfect t square
For (B) I got stuck at expanding $(a)(a + 1)(a+2) (a + 3)$
Could someone help please ?