Problem:
We are given a quadratic polynomial:
\[
(\alpha - 1)x^2 + \alpha x + 1
\]
It is also given that one of the zeroes of this polynomial is \(x = -3\). We are to find the value of \(\alpha\).
Step 1: Substitute the known root into the polynomial
Since \(-3\) is a zero of the polynomial, it must satisfy the equation:
\[
(\alpha - 1)(-3)^2 + \alpha(-3) + 1 = 0
\]
Now simplify step-by-step:
\[
(\alpha - 1)(9) - 3\alpha + 1 = 0
\]
\[
9\alpha - 9 - 3\alpha + 1 = 0
\]
\[
(9\alpha - 3\alpha) + (-9 + 1) = 0
\Rightarrow 6\alpha - 8 = 0
\]
Step 2: Solve for \(\alpha\)
\[
6\alpha = 8 \Rightarrow \alpha = \frac{8}{6} = \frac{4}{3}
\]
Final Answer:
The value of \(\alpha\) is \(\frac{4}{3}\).