Answer:
Step-by-step explanation:
If you plot this point and the directrix on a coordinate plane, you can see that the directrix is 1/4 of a unit below the vertex. Since, by nature, a parabola opens in the direction opposite the directrix and "hugs" the focus, this is a positive x-squared parabola (meaning it opens upwards). The formula for this type of a parabola is, in vertex form,

where p is distance (in units) between the vertex and the directrix and h and k are the coordinates of the vertex. For us, p = .25, h = 7, and k = -6. Filling in our formula:

Simplify the left side to
which simplifies, in its entirety, to

(x-5)(x+2)=0
roots: x=5 and x= -2
see attached photo for steps
-9x+2y = -36
when x=0 ; 2y = -36
so y = -18
then y-intercept(x=0) is -18
Answer:
Boys(B) + Girls(G) = 85 ----(1)
Mangoes = 380
Each boy gets 4mangoes
Each girl gets 5mangoes
4B + 5G = 380 -------(2)
from (1) B = 85 - G
Substitute B in (2)
4(85 - G) + 5G = 380
360 - 4G + 5G = 380
G = 380 - 360 = 20
from (1) B = 85 - 20 = 65
Therefore number of boys = 65 and girls = 20
Ratio of boys and girls = 65 : 20 = 13 : 4