Answer
$y=x+2$
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 rule, that the product of the slopes of two perpendicular lines equals $-1$.
Here, a perpendicular line is $y=-x$.
In this form, the slope can be seen as the coefficient of $x$, which is $-1$.
Therefore our line's slope $m$ can be calculated as:
$m\times(-1)=-1$
$m=\dfrac{-1}{-1}=1$
Therefore, using the point $(-1, 1)$ and the slope $1$, the equation can be written as:
$y-1=1(x-(-1))$
$y-1=x+1\\
y=x+1+1\\
y=x+2$
