Answer: 0 ≤ x ≤ 4
Explanation:
The cost equation can be written as:
y = $2 + $0.75*x
Where x is the number of ounces that you buy.
If you can spend between $2 and $5, then we have the inequality:
$2 ≤ y ≤ $5
replacing y by the above equation:
$2 ≤ $2 + $0.75*x ≤ $5
Now let's solve this for x.
$2 - $2 ≤ ($2 + $0.75*x) - $2 ≤ $5 - $2
$0 ≤ $0.75*x ≤ $3
now we can divide bt $0.75 in the 3 sides:
$0/$0.75 ≤ ($0.75*x)/$0.75 ≤ $3/$0.75
0 ≤ x ≤ 4
Then the domain is:
D: 0 ≤ x ≤ 4
or we can also write this as:
D = x ∈ [0, 4]