The range is {-37,-25,-13,-1}. So you need to figure out what four numbers from this list of numbers (1,2,3,4,5,6,7,8), when applied to this function, ( f(x)=-6x+11 ), equals these numbers that are in the range {-37,-25,-13,-1}.
So you apply each of these numbers (1,2,3,4,5,6,7,8) into the function (f(x)=-6x+11) one by one.
f(1)=-6(1)+11=5 f(2)=-6(2)+11= -1 f(3)=-6(3)+11= -7 f(4)=-6(4)+11= -13 f(5)=-6(5)+11= -19 f(6)=-6(6)+11= -25 f(7)=-6(7)+11= -31 f(8)=-6(8)+11= -37 As you can see, f(2),f(4),f(6),and f(8) equal the numbers that are in the range {-37,-25,-13,-1}.
y is the number of minutes, so that will be on the left of the equal sign, not part of the math side of the actual equation, because it's the answer.
1.5x is the mx part because it's 1.5 minutes for each extra patty. So that would explain the x attached to it. so for each extra patty you add, that's what x would be.
The + 2.5 at the end, is just the time for the initial patty.
