A = √2 + 3 - 6√2 + 4 = 7 - 5√2
A = 7 - 5√2
B =( √2 + 3 ) ( 6√2 - 4) = 6√4 + 18√2 - 4√2 - 12=6×2 + 14√2 - 12= 14√2
B = 14√2
A + B = 7 - 5√2 + 14√2 = 7 + 9√2
A - B = 7 - 5√2 - 14√2 = 7 - 19√2
A × B = ( 7 - 5√2) × 14√2 = 7×14√2 - 5×14×√4= 98√2 - 70×2 = 98√2 - 140=
= 14 ( 7√2 - 10)