4 а.
2x√3 = √(4x²*3)= √(12x²)
б
4/x²√(x⁶/8) = √(16/x⁴ * x⁶/8) = √(2x²)
5 а
(2√11 + 3)(2√11 - 3) = (2√11)² - 3² = 4*11 - 9 = 44 - 9 = 35
б
( 2√3 + √2)² - 4√6 = (2√3)² +2*2√3*√2 + (√2)² - 4√6 = 12 + 4√6 + 2 - 4√6 = 14
6a
14/√7 = (14*√7) / (√7*√7) = (14*√7)/7 = 2√7
б
11/(6+√3) = 11(6-√3)/(6+√3)(6-√3) = 11(6-√3) / (36-3) = 11(6-√3)/33= (6-√3)/3