It's easiest to multiply (2sqrt(7)+sqrt(5))(2sqrt(7)-sqrt(5))(2√7+√5)(2√7−√5) first...
(2sqrt(7)+sqrt(5))(2sqrt(7)-sqrt(5))(2√7+√5)(2√7−√5) is of the form
(a+b)(a-b) = a^2 - b^2(a+b)(a−b)=a2−b2 with a=2sqrt(7)a=2√7 and b=sqrt(5)b=√5
So:
(2sqrt(7)+sqrt(5))(2sqrt(7)-sqrt(5))(2√7+√5)(2√7−√5)
=(2sqrt(7))^2-sqrt(5)^2 = (4*7)-5 = 28 - 5 = 23=(2√7)2−√52=(4⋅7)−5=28−5=23
Then
(2sqrt(7)+sqrt(5))(sqrt(3)+sqrt(2))(2sqrt(7)-sqrt(5))(2√7+√5)(√3+√2)(2√7−√5)
= (2sqrt(7)+sqrt(5))(2sqrt(7)-sqrt(5))(sqrt(3)+sqrt(2))=(2√7+√5)(2√7−√5)(√3+√2)
=23(sqrt(3)+sqrt(2)) = 23sqrt(3)+23sqrt(2)=23(√3+√2)=23√3+23√2