Here is how to find the equation of the line using point-slope form
Formula for the equation of a line in point-slope form: y - y₁ = m(x - x₁)
Now that we have the formula, we plug in what we are given.
y - 9 = 4(x + 3)
We can covert this into slope-intercept form by solving for y.
[tex]y - 9 = 4(x + 3)\\\\y - 9 = 4x + 12\\\\y = 4x + 21[/tex]
Our equation for this line is: y = 4x + 21.
We can prove this by graphing the line, like so: