a+b=-2,ab=-3 求a(a05-b05)-a(a+b)05
问题描述:
a+b=-2,ab=-3 求a(a05-b05)-a(a+b)05
05是平方的意思
答
原式=a(a²-b²)-a(a+b)² =a(a+b)(a-b)-a(a+b)²=(a+b)[a(a-b)-a(a+b)]=-2[a(a-b)+2a]=-2[a²-ab+2a]=-2(a²+2a+3)=-2[a(a+2)+3] 【a+2=-b】=-2[-ab+3]=-2*6=-12