-1/4x²+1/8x+1/2x²-1/8x+3,其中x=-2,先化简,再求值_数学解答

-1/4x²+1/8x+1/2x²-1/8x+3,其中x=-2,先化简,再求值

人气：299 ℃　时间：2020-03-27 18:49:50

解答

-1/4x²+1/8x+1/2x²-1/8x+3
=1/2x²-1/4x²+1/8x-1/8x+3
=1/4x²+3
=1/4*(-2)²+3
=-1+3
=2