# Determine dependencies, might be cramer's rule

I have the following problem,

Determine how $x_1(\alpha)$ depends on $\alpha$ when $x_1(\alpha)$ is the first component of the solution of the system $Ax = b$, where

A = $\begin{bmatrix}2 & 1 & 1\\1 & -1 & 4\\1 & 1 & -2\end{bmatrix}$ and B = $\begin{bmatrix}-2\\\alpha\\1\end{bmatrix}$

I'm think Cramer's rule but am not sure what that would prove.