(1-3a)(1+3a)(1+9^2)(1+81a^4),其中a=-1/2_数学解答

(1-3a)(1+3a)(1+9^2)(1+81a^4),其中a=-1/2

人气：139 ℃　时间：2020-09-18 19:02:12

解答

(1-3a)(1+3a)(1+9a^2)(1+81a^4),
=(1-9a^2)(1+9a^2)(1+81a^4)
=(1-81a^4)(1+81a^4)
=1-81²a^8
=1-6561/256
=-6305/256