168.
1) 1 - 1 = 3√2 +4 - (3√2 -4) = 3√2 +4 - 3√2 +4 =
3√2 -4 3√2 +4 (3√2 -4)(3√2 +4) (3√2)² - 4²
= 8 = 8/2 =4
9*2 - 16
2) 1 + 1 = 5-2√6 + 5+2√6 = 10 = 10
5+2√6 5-2√6 (5+2√6)(5-2√6) 25 - 4*6
3) 1 - 1 = 11+2√30 - 11+2√30 = 4√30 = 4√30
11-2√30 11+2√30 (11-2√30)(11+2√30) 121 - 4*30
4) √5 - √3 + √5 + √3 = (√5 - √3)² + (√5 +√3)² =
√5 + √3 √5 - √3 (√5 +√3)(√5 - √3)
= 5 - 2√15 +3 + 5+2√15+3 = 16/2 =8
5-3