Hello!
Let's convert the equation, 3x + 4y = 7, into slope-intercept form:
⇒ slope-intercept form is where the y-variable is isolated to one side

The other line that is parallel to the equation: has the same slope
==> thus this other's line slope is -3/4
Let's set up the point-slope form for this other line:

- (x₀,y₀): (-3, -9) <-- any point on the line
- m: -3/4 <-- slope of line

<== Answer
Hope that helps!