Answer:

Step-by-step explanation:
The equation of a horizontal parabola in the standard form:

(h, k) - vertex
if a > 0, then open right
if a < 0, then open left
We have the vertrex (-1, -3) and the parabola is open left (a < 0).
Therefore the equation of a given parabola could be:

I believe your answer is -0.25n+0.75
6+6=12
8+4=12
or if you mean algebraic equation:
6+x=12
x+4=12
Answer:
25h-35=440
440+35=25h
475=25h
475÷25=h
h=19
19 hours
It will take 19 hours of lessons.