Explanation:
the general slope intercept form is
y = ax + b
a is the slope.
b is the y-intercept (the point, where the line crosses the y-axis, meaning the y value when x=0).
we get b by using the point coordinates in the equation and solve for b :
-8 = -3×3 + b = -9 + b
1 = b
so, the full line equation is
y = -3x + 1