4x²-2x²-﹙5x²-3x²+二分之三x-y-1﹚其中x＝3 y＝1先化简再求值

题目

4x²-2x²-﹙5x²-3x²+二分之三x-y-1﹚其中x＝3 y＝1先化简再求值

答案

4x²-2y²-﹙5x²-3y²+二分之三x-y-1﹚
=-x²+y²-3/2x+y+1
=-3²+1²-3/2x3+1+1
=-9+1-4.5+2
=-10.5