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
She walked 4.5 miles. just multiply the miles she walked Tuesday by 1.2.
Answer:
you need 100ml of 5X TAE and 400ml of water.
Step-by-step explanation:
You need to use a rule of three:

where:

and

Therefore:


Then just rest the TAE volume to the final Volume and you get the amount of water that you need to reduce the concentration.