化简合并同类项（初一题目）式子如下

a-1/2(a+a/2)a-1/2(a-a/2)a-1/2*a^2/2=a-1/2(3a/2)a-1/2(a/2)a-1/4*a^2=a-3/4*a^2-1/4*a^2-1/4*a^2=a-(3/4+1/4+1/4)*a^2=a-5/4*a^2 再问： a^2+(a/2)^2-1/2(a+a/2)a-1/2(a-a/2)a-1/2*a^2/2这个呢？ 再答： a^2+(a/2)^2-1/2(a+a/2)a-1/2(a-a/2)a-1/2*a^2/2 =a^2+a^2/4-3a^2/4-a^2/4-a^2/4 =(1+1/4-3/4-1/4-1/4)a^2 =0 采纳吧