Answer:
y = -3x
Step-by-step explanation:
You want the slope-intercept equation of the line with slope -3 through the point (-1,3).
Point-slope form
The equation of the line with slope m through point (h, k) can be written ...
y -k = m(x -h)
For slope -3 and point (-1, 3), the equation is ...
y -3 = -3(x +1)
Slope-intercept form
Eliminating parentheses gives ...
y -3 = -3x -3
Adding 3 gives the equation ...
y = -3x
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Additional comment
As you can see, the y-intercept is 0.
