Question 824392
A) let u = square root (2) + square root (5)
   then we can rewrite problem as
   (u + square root(3)) * (u - square root(3))
    u^2 - 3
    (2 + 2*square root(2)*square root(5) +5) - 3
    (2 +2*square root(10) +5 -3)
    (4 +2*square root(10))
    2*(2 + square root(10)) 
B) let v = square root(2) - square root (5)
   then we can rewrite problem as
   (square root(3) + v) * (square root(3) - v)
    3 - v^2
    3 - (2 -2*square root(2)*square root(5)+5)
    3 - (2 -2*square root(10)+5)
    3 - 2 +2*square root(10) - 5
    2*square root(10) - 4
    2*(square root(10) - 2)
now we are asked what is C = AB
C = (2*square root(10) + 4) * (2*square root(10) -4)
C = 4*10 - 16
C = 40 -16
C = 24