Jawabanmu

2014-08-26T17:43:34+07:00
6√72+6√8-√20+3√45= 6 √36x2 + 6 √4x2 - √4 x 5 +3√9x5 = 6x6√2 + 6x2√2 -2√5+3x3√5 = 36√2 +12√2 - 2√5 + 9√5 = 48√2 - 7√5 √42-2√13+√1024+√32= √16x2 - 2 √13 + 32 + √16x2 = 4√2 - 2√13 + 32+4√2 = 8√2 - 2√13 + 32
  
(5+2√6)(5-2√6)
(a+b)(a-b) = a
²-b², maka 
(5+2√6)(5-2√6) = 5²-√6² = 25 - 6 = 19