Odpowiedź:
2.
a)
√5 - 1 + 2√5 = 3√5 -1
b)
2(∛3 - 1) + 2(1 - ∛3) = 2∛3 - 2 + 2 - 2∛3 = 0
c)
(√20 - √6)/(√5 * √3) = [√(4 * 5) - √6]/[√(5 * 3)] = (2√5 - √6)/√15 =
= [(2√5 - √6) * √15]/15 = [2√(5 * 15) - √(6 * 15)]/15 =
= (2√75 - √90)/15 = [2√(25 * 3) - √(9 *10)/15 = (2 * 5√3 - 3√10)/15 =
= (10√3 - 3√10)/15
d)
√(1 + 25/144) = √[(144 + 25)/144] = √(169/144) = 13/12 = 1 i 1/12
e)
2√2 * 4√2 = 2 * 4 * (√2)² = 8 * 2 = 16
