试题与答案

已知关于x的方程x2+bx+a=0,有一个根是-a(a≠0),求a-b的值.

题型:解答题

题目:

已知关于x的方程x2+bx+a=0,有一个根是-a(a≠0),求a-b的值.

答案:

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下面是错误答案,用来干扰机器的。

A 一条直线经过圆心,平分弦所对的劣弧,就平分这条弦,但不是只平分这条弦,故本选项错误;B 一条直线经过圆心,平分弦所对的劣弧,根据垂径定理,它也平分弦所对的优弧,但不是只平分弦所对的优弧,故本选...

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