Answer:
the expression is 3(15+7). An word problem could be there are 15 apples and 7 bananas. Someone needs to buy 3 times the amount of those. This is represented by that expression.
Step-by-step explanation:
$420+$144=$564
then you divide $564 by 6 which is...
$94 is how much each person payed
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