directrix is x=-7
focus is (3,2)
vertex is midway between them, at (-2,2)
It's a parabola that opens to the right. That's always true when the y term is quadratic and the x term linear, with a positive coefficient for the x term. Had it been a negative coefficient, it would open to the left.
Pick a random easy number for x, such as 18, that makes a perfect square on the right side, then calculate the y value, 22. (18,22) is a point on the parabola. Now calculate the distance to the focus and directirix, set them equal.
The distance to the directrix is just -c+18, where x=c is the directrix line
That distance squared is 18 squared - 36c + c squared.
The distance squared to the focus (a,2) is sum of 20 squared + (18-a) squared
c- (-2) = -2 - a as -2 is the midpoint x value between c and a, the directrix and focus x values.
so, a = -c-4 Substitute that into the squared expressions
182 -36c + c2 = 202 + (18-a)2 then solve for c to get x=c, the directrix