Jawabanmu

2014-06-20T17:02:36+07:00
F(-4) = 2(-4)³ + 5(-4)² - 4(-4) + k = 0

<=> -128 + 80 + 16 + k = 0
<=> k = 32
1 5 1
2014-06-20T17:38:32+07:00
f(x) = 2x³ + 5x² - 4x + k
f(-4) = 2(-4)³ + 5(-4)² -4(-4) + k
  0    = -128 + 80 + 16 + k
  k    = 128 - 96
Jadi, nilai k = 32