Question

Diketahui suku banyak p(x) = 2x pangkat 4 + 3x³ - x² - ax + 3. tentukan nilai a jika :
2p(1) - 5 = 3

Answer 1

P(x)=2x⁴+ 3x³ - x² - ax + 3 p(1)=2(1)⁴+3(1)³-(1)²-a(1)+3 =2+3-1-a+3 =7-a 2p(1)-5=3 2(7-a)-5=3 14-2a-5=3 9-2a=3 -2a=-6 a=3

Answer 2

P(x) = 2x^4 + 3x³ - x² - ax + 3
2p(1) - 5 = 3 ⇔ 2p(1) = 8 ⇔ P(1) = 4
p(1) = 2(1)^4 + 3(1)³ -(1)² - a(1) + 3
  4   = 2 + 3 - 1 - a + 3
  4   = - a + 7
a = 7 - 4 = 3
Jadi, nilai a = 3