We are given
The equation that models this trip is T= 36x + 60
T represents the total cost for the group to take the trip and
X equals the number of people going
we know that
Domain is all possible values of x for which any function is defined
Since, number of people can neither be negative nor in decimals
so, x can not be negative or in decimals
now, we will check each options
option-A:
x=40
This is positive and whole number
so, this can be domain
so, this is TRUE
option-B:
x=60
This is positive and whole number
so, this can be domain
so, this is TRUE
option-C:
0< x< 40
It also includes decimals numbers
and we know that
x can not be in decimals
so, this is FALSE
option-D:
0< x< 39
It also includes decimals numbers
and we know that
x can not be in decimals
so, this is FALSE
12.75
PROOF:
find all the m's first
3m+3m+m+m=8m
8m=102
Divide both sides, and you get
12.75
It is understood without being written that the slope of this line is 1. If we rewrite the point-slope form of the line it would be y-8=1(x-4) where 1 is the slope. We move the -8 over by addition to get y = 1x-4+8, or, simplified, y=x+4, the first choice in your answers.
