Answer:
a = 1
Step-by-step explanation:
Since x = - 1 is a zero of p(x) then p(- 1) = 0
Substitute x = - 1 into p(x)
p(- 1) = a(- 1)² - 3(a - 1)(- 1) - 1 = 0, that is
a + 3(a - 1) - 1 = 0
a + 3a - 3 - 1 = 0
4a - 4 = 0 ( add 4 to both sides )
4a = 4 ( divide both sides by 4 )
a = 1