Answer:
a = 21
Step-by-step explanation:
If x = h is a zero of a polynomial then f(h) = 0, thus
p(- [tex]\frac{1}{3}[/tex] ) = 27( - [tex]\frac{1}{3}[/tex] )³ - a(- [tex]\frac{1}{3}[/tex] ) - (- [tex]\frac{1}{3}[/tex] ) + 3 = 0, that is
27 (- [tex]\frac{1}{27}[/tex] ) - [tex]\frac{1}{9}[/tex] a + [tex]\frac{1}{3}[/tex] + 3 = 0
- 1 - [tex]\frac{1}{9}[/tex] a + [tex]\frac{10}{3}[/tex] = 0 ( multiply through by 9 to clear the fractions )
- 9 - a + 30 = 0
- a + 21 = 0 ( subtract 21 from both sides )
- a = - 21 ( multiply both sides by - 1 )
a = 21
