The equation of a line can be written in point-slope form as:

$y - y_1 = m(x - x_1)$

where $(x_1, y_1)$ is a point on the line and $m$ is the slope of the line.

In your case:

• The point is $(1, -3)$.
• The slope is $-3$.

Substituting these values into the point-slope form:

$y - (-3) = -3(x - 1)$

Simplify this equation:

$y + 3 = -3(x - 1)$

Now, distribute the $-3$ on the right-hand side:

$y + 3 = -3x + 3$

Finally, subtract 3 from both sides to get the equation in slope-intercept form:

$y = -3x$

So, the equation of the line is:

$y = -3x$

Would you like more details or have any questions?

Here are 5 related questions to explore:

1. How do you convert from point-slope form to slope-intercept form?
2. What is the general form of the equation of a line?
3. How do you find the equation of a line given two points?
4. What is the slope of a vertical line?
5. How do parallel lines relate in terms of their slopes?

Tip: Always remember that parallel lines have the same slope, while perpendicular lines have slopes that are negative reciprocals.