Question

if X equal to under root 5 + under root 2 upon under root 5 minus under root 2 and B equal to under root 5 minus under root 2 upon under root 5 + under root 2 so that 3a squareclass 4 a b minus 3 b square equal to 4 + 56 upon 3 under root 10 ​

Answer 1

from which book and exercise