Answer:
C. {-1, 5, 8}
Step-by-step explanation:
Use each of the domain values in the function to see what the corresponding range value is.
f(-1) = 5 -3(-1) = 8
f(0) = 5 -3(0) = 5
f(2) = 5 -3(2) = -1
The range is the set of numbers {-1, 5, 8}.
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<em>Additional comment</em>
The values in a set are generally listed lowest to highest. The coefficient of x in the equation for f(x) is negative, meaning the lowest range value will correspond to the highest domain value. If you start by finding f(2) = -1, you immediately eliminate all answer choices except B and C.
Those choices differ only in the middle value, so you can tell which is correct by evaluating f(x) for the middle domain value: f(0) = 5. Only one answer choice has both -1 and 5 in the set.
(There are two answers here: how you work the problem, and how you game a multiple choice question.)
Adult ticket (a) = $5
Child ticket (c) = $2
785 tickets = $3280
a + c = 785 tickets
5a + 2c = $3280
c = 215 child tickets
a = 570 adult tickets
570 + 215 = 785 tickets
5(570) + 2(215) = $3280
There were 215 child tickets sold on Saturday
