The answer is f(x) = 5 - 2x
Function form means just replace y with f(x).
So given 8x + 4y = 20:
Subtract 8x
4y = 20 - 8x
Divide both sides by 4
y = 5 - 2x
991 if you round it off.
990.8
Above 5 so go up one
Answer:
6,840 casts
Step-by-step explanation:
Assuming that every actor can play each of the 4 roles and that each role is different, the number of possible casts including at least one of sir Ian and Patrick is given by the total number of possible casts (permutation of 4 out of 12 actors), minus the number of casts without sir Ian and Patrick (permutation of 4 out of 10 actors):

There are 6,840 possible casts.
The median is 82
The mode is 73
The mean is 80.8
We want to get rid of the stuff in the denomenator
gcd of the denomenator is 2x
but wait, we can get rid of the deonmenator in the numerator by multiplying by 4x
muliplty the whole thing by 4x/4x
we get