(3x²-2x²-2y)÷(x+y) 化简【3x²-2x(x+y)+y(2x-y)】÷(x+y)其中x=1/2 y=1/3

问题描述:

(3x²-2x²-2y)÷(x+y) 化简【3x²-2x(x+y)+y(2x-y)】÷(x+y)其中x=1/2 y=1/3

[3x2-2x(x+y)+y(2x-y)]÷(x+y)=[x2-2x(x+y)+x2+2xy+y2+x2-2y2]÷(x+y)=[x2-2x(x+y)+(x+y)2+x2-2y2]÷(x+y)=[(x-(x+y))2+x2-2y2]÷(x+y)=(x2-y2)÷(x+y)=x-y在将数据x=1/2 y=1/3代入计算即得:1/6.