Answer
The $y$-intercept is $2$.
The slope is $-\frac{1}{2}$.
See the graph below.
Work Step by Step
First, we have to get the equation's slope-intercept form, that is $y=mx+b$:
Subtract $x$ from both sides, then divide both sides by $2$ afterwards to obtain:
\begin{align*}
x+2y-x&=4-x\\
2y&=-x+4\\
\frac{2y}{2}&=\frac{-x+4}{2}\\
y&=-\frac{1}{2}x+2\end{align*}
This form of the equation is the slope-intercept form.
In this form, the slope of the line equals to the coefficient of $x$ (which is $m$) and the $y$-intercept equals to the constant $b$.
Therefore in the equation $y=-\frac{1}{2}x+2$:
The $y$-intercept is $2$.
The slope is $-\frac{1}{2}$.
In order to graph the line, we have to sketch the $y$-intercept, that is $(0,2)$.
As the slope is $-\frac{1}{2}$, we can find another point that we can also sketch.
The slope is the change in $y$ for every $1$ unit change of $x$.
Thus, a slope of $-\frac{1}{2}$ means a $1$-unit increase in $x$ will result to a $-\frac{1}{2}$-unit increase (or $\frac{1}{2}$-unit decrease) in $y$. This is equivalent to a $1$ unit decrease in $y$ for a $2$-unit increase in $x$.
Using $(0,2)$ as the starting point and a slope of $-\frac{1}{2}$, the coordinates of another point on the line would be:
$(0+2, 2-1)=(2,1)$
Plot the two points then connect them using a straigiht line.
Refer to the graph above,
