已知方程x²-3x-8=0的两个解分别为a、b，则a+b、ab值分别是（） A．

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问题选择题

已知方程x²-3x-8=0的两个解分别为a、b，则a+b、ab值分别是（）

A．3，-8

B．-3，-8

C．-3，8

D．3,8

答案

题目分析：根据根与系数的关系x₁+x₂=-,x₁x₂=解题．

∵已知方程x²-3x-8=0的两个解分别为a、b，

∴x₁+x₂=-,x₁x₂=

故选A.

考点: 根与系数的关系．

听力题

单词拼写：（每小题一分，共10分）

小题1:Fire d_____________ several stores in the business district.

小题2:What’s her a____________ towards the plan? Is she for or against?

小题3: You should not talk about things that don’t c___________ you.

小题4:He is going to make a long j_____________.

小题5:G______________ from our school are working all over the island.

小题6:Dogs _____________(认出) people by their smell.

小题7: It was really very dangerous; you might have __________(伤害)him seriously.

小题8:For him, this will be an ___________ (完全地) new hobby.

小题9: Have you made the examination _________________(日程表)?

小题10:The city lay in _______________(废墟) after the earthquake.

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