Answer:
17
Step-by-step explanation:
Use ratio method
98:2
850:x
so, x = (850 x 2) divided by 98 = 17.3469388
Round it to nearest whole number = 17
14 3/5 as a decimal would be 14.6
The line is called the directrix. Here we have a vertical directrix, so a parabola sideways from usual.
Geometry is best done with squared distances. The squared distance from an arbitrary point (x,y) to the vertical line x=2 is

We equate that to the squared distance of (x,y) to the focus (-2,0):



We could call that done. A more standard form might be