Jawabanmu

2014-07-20T14:36:41+07:00
  (x^{2}  - y^{2}) ^{2} =  8^{2}
 x^{4} + y^{4} - 2 x^{2}  y^{2} =64
[tex] x^{4} + y^{4} - 2.4=64
[tex] x^{4} + y^{4} = 72