40.若a與a + 2為方程式x 2 + 2x + k = 0的解,則a之值為何?
(A) −4
(B) −2
(C) 0
(D) 2
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統計: A(34), B(262), C(44), D(10), E(0) #1996586
統計: A(34), B(262), C(44), D(10), E(0) #1996586
詳解 (共 1 筆)
#3367035
ax2+bx+c=0
兩根之和-b/a
x2+2x+k=0
兩根之和=-2/1=-2
a+(a+2)=-2
a=-2...(B)
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