a2+b2=2,那么代数式(a2-2ab-3b2)-(3a-2ab-b2)的值是?
问题描述:
a2+b2=2,那么代数式(a2-2ab-3b2)-(3a-2ab-b2)的值是?
答
a2-2ab-3b2)-(3a²-2ab-b2)
=-2a²-2b²
=-2(a²+b²)
=-4