Answer:
Step-by-step explanation:
We have that the focus is at (p,0) and that the directrix is x=-p. Take the point (-p,0) of the directrix. We know that the vertex of the parabola is at the middle point ot the line segment that joins the points (p,0) and (-p,0). To get the middle piont, we take the average coordinate by coordinate. That is, the middle point is . The general formula of a parabola of vertex (h,k) that opens to the right or to the left is given by
Where |p| is the distance from the focus to the vertex. If the parabola opens to the right, then p>0 and p<0 otherwise. In our case, h =0=k, so we get that
If you are just dividing percent's, then each grade would have 12.5 percent.
Answer:
$60
Step-by-step explanation:
Let's say we need t $2 bills and v $5 bills.
We need 9 more $2 bills than $5 bills, so:
t = 9 + v
We also know that the amount of money in t $2 bills is 2 * t = 2t. The amount of money in v + 9 $5 bills is 5 * (v + 9) = 5v + 45. These amounts are equal:
5v + 45 = 2t
Plug v + 9 in for t in 5v = 2t + 18:
5v = 2t + 18
5v = 2 * (9 + v) + 18
5v = 18 + 2v + 18
3v = 36
v = 12
We have 12 $5 bills, so that total cost is 12 * 5 = $60.
<em>~ an aesthetics lover</em>