(A)条件(1)充分,但条件(2)不充分.(B)条件(2)充分,但条件(1)不充分.
问题:
- (A)条件(1)充分,但条件(2)不充分.
- (B)条件(2)充分,但条件(1)不充分.
- (C)条件(1)和(2)单独都不充分,但条件(1)和条件(2)联合起来充分.
- (D)条件(1)充分,条件(2)也充分.
- (E)条件(1)和(2)单独都不充分,条件(1)和条件(2)联合起来也不充分.
x2+px+q=(x-9)(x+11).
(1)p=-2,q=-99; (2)p=2,q=-99.
x2+px+q=(x-9)(x+11).
(1)p=-2,q=-99; (2)p=2,q=-99.