(1+0.23+0.34)x(0.23+0.34+0.65)-(1+0.23+0.34+0.65)x(0.23+0.34)=多少,
问题描述:
(1+0.23+0.34)x(0.23+0.34+0.65)-(1+0.23+0.34+0.65)x(0.23+0.34)=多少,
老兄看不懂!请仔细一点
答
设1+0.23+0.34+0.65=a
原式
=(a-0.65)(a-1)-a(a-1-0.65)
=a^2-a-0.65a+0.65-a^2+a+0.65a
=0.65