a² -a -1 = 0a² = a+1,a⁸ = (a+1)⁴a¯¹ = a-1,a¯⁴ = (a-1)⁴代数式a的8次方加｛7乘a的负4次方｝= (a+1)⁴ + 7(a-1)⁴= (a+1)⁴ -(a-1)⁴ + 8(a...