#### Answer

$y$;
$x$;
$-1$

#### Work Step by Step

The x-intercept can be found by setting $y=0$ in the given equation then solving for $x$.
Thus, the x-intercept of $2y=x+1$ is:
$2(0)=x+1
\\0=x+1
\\0-1=x
\\-1=x$
Therefore, the missing expressions in the given statements (in order) are:
$y$;
$x$;
$-1$