Answer
$y-1=-(x-1)$
Work Step by Step
The equation of a line in the point-slope form is the following:
$y-y_1=m(x-x_1)$, where $m$ is the slope and the point $(x_1,y_1)$ is on the graph.
In order to determine the equation of a line, we have to calculate the slope. For this, we can use the formula:
$m=\dfrac{y_2-y_1}{x_2-x_1}$, where the two points on the line are $(x_1, y_1)$ and $(x_2,y_2)$.
Here, if we plug in the given points we get:
$m=\dfrac{3-1}{-1-1}=\dfrac{2}{-2}=-1$
Therefore using the point $(1, 1)$ and the slope $-1$, the equation can be written in point-slope form as:
$y-1=-(x-1)$