1/2x-(-1/2x+1/3y²)-2(x+1/3y²)

问题描述:

1/2x-(-1/2x+1/3y²)-2(x+1/3y²)
过程要详细、去括号后合并同类项

=1/2x+1/2x-1/3y²-2x-2/3y²
=(1/2x+1/2x-2x)+(-1/3y²-2/3y²)
=-x-y²