X : the gas used by first car in 1 particular week
y : the gas used by second car in 1 particular week

i dont have time to do all of it (sorry)
but this is how you do the point and slope questions:
use the equation: y-y1 = m(x - x1)
y1 is the y point you are given
x1 is the x point you are given
m is your slope
substitute all of those in from the question
the first one is:
y --4 = -5/6(x-8)
-- turns into a plus so the answer would be
y+4 = -5/6(x-8)
1 (((m^(-1)) (m^5)) / (m^(-2)))^(-3) =1/m^18
I think the answer would be B :)
Answer: There isn't a possible way you can really answer this question because I don't know how much one piece cost in the first place , but if I had to guess I would say around 50-80 dollars for a cake is enough for 57 guests.
explanation: I say this because I know usually cakes for a decent amount of people are around 50-80 dollars.