先化简,再求值:[5a^4*a^2-(3a^6)^2/(a^2)^3]/(-2a^2)^2,其中a=-5_数学解答

先化简,再求值:[5a^4*a^2-(3a^6)^2/(a^2)^3]/(-2a^2)^2,其中a=-5

人气：467 ℃　时间：2020-02-04 05:25:56

解答

[5a^4*a^2-(3a^6)^2/(a^2)^3]/(-2a^2)^2
=(5a^6-9a^12/a^6)/(4a^4)
=(5a^6-9a^6)/(4a^4)
=-4a^6/(4a^4)
=-a^2