4x^2y+8y-4+x^2y+1,其中x=-1/2,y=2先化简再求值,急_数学解答

4x^2y+8y-4+x^2y+1,其中x=-1/2,y=2
先化简再求值,急

人气：478 ℃　时间：2020-06-05 11:48:16

解答

楼上错

4x^2y+8y-4+x^2y+1
=5x^2y+8y-3
=5x(-1/2)²x2+8x2-3
=5x1/4x2+16-3
=2.5+13
=15.5确定吗？确定