162 DS. ax^2+bx+c where a, b and c are integers, does the system have a integer

leeguoyan

162 DS. ax^2+bx+c where a, b and c are integers, does the system have a integer solution?
1) a<0
2)c>0

what is answer？

liyang229

the only way for you to determine whether a function has solution is based on  delta= b^2 -4ac=>0.
if delta = 0, there is one solution,
if delta >0. there are two solution.
if delta <0. no solution.

thus, based on this question,  the answer is E , i think.  there is no way for you to determine delta.


but i am not guarantee.you may check with others.

tibet

方程解的问题，看b^2-4ac的，BOTH的话-4ac肯定是正数，那就是2个解，选C回答NO。。
等等……！integer solution？好吧。。是E

大家好好感谢尘未吧，呵呵。仔细看这里
http://forum.chasedream.com/GMAT_Math/thread-433556-1-1.html

leeguoyan

多谢多谢