a*****g
发帖数: 1320 | 1 【 以下文字转载自 SanFrancisco 讨论区 】
发信人: ashuang (东洛杉矶推妈+股票大妈), 信区: SanFrancisco
标 题: mathscounts 数学题求助(4)
发信站: BBS 未名空间站 (Wed Jan 19 00:02:32 2011, 美东)
1) The solutions of x2 +bx+c=0 are each 5 more than the solution of x2+7x+3=0. What are the value of b and c? Express your answer as an ordered pair (b,
c)
2) A cubic equation of the form x3+ bx2+cx+d==0 has solutions x=3, x=4 and x
=5. What are the value of b, c, and d? Express your answer as an ordered
triple (b,c,d)
3) What is the sum of the reciprocals of the solutions of x3-3x2-13x+15=0?
Express your answer as a common fraction
4) What is the sum of the squares of the solutions of x3-15x2+66x-80=0?
5) The solutions of X3-63x2+cx-1728=0 form a geometric sequence. What is the
value of c?
Thanks a lot! | x******i
发帖数: 3022 | 2 出这种难度的题，是对考生的侮辱。
3=0. What are the value of b and c? Express your answer as an ordered pair (
b,
x
【在 a*****g 的大作中提到】
: 【 以下文字转载自 SanFrancisco 讨论区 】
: 发信人: ashuang (东洛杉矶推妈+股票大妈), 信区: SanFrancisco
: 标 题: mathscounts 数学题求助(4)
: 发信站: BBS 未名空间站 (Wed Jan 19 00:02:32 2011, 美东)
: 1) The solutions of x2 +bx+c=0 are each 5 more than the solution of x2+7x+3=0. What are the value of b and c? Express your answer as an ordered pair (b,
: c)
: 2) A cubic equation of the form x3+ bx2+cx+d==0 has solutions x=3, x=4 and x
: =5. What are the value of b, c, and d? Express your answer as an ordered
: triple (b,c,d)
: 3) What is the sum of the reciprocals of the solutions of x3-3x2-13x+15=0?
|
|
