Answer
$y = -3x + 5$
Work Step by Step
Because we are given a point on the graph along with the slope, it makes sense for us to use the point-slope form of an equation, which is given by the following formula:
$y - y_1 = m(x - x_1)$
where $m$ is the slope of the graph and $(x_1, y_1)$ is a point on that graph.
Substitute $m=-3, x=2, \quad \text{ and } \quad y=-1$ into the point-slope form above to obtain:
$y - (-1) = -3(x - 2)$
$y + 1 = -3x + 6$
Convert this equation into the slope-intercept form by subtracting $1$ from each side of the equation and isolating $y$ on the left side of the equation:
$y = -3x + 6 - 1$
$y = -3x + 5$
