9514 1404 393
Answer:
A (and C)
Explanation:
A relationship that is a direct proportion is described by the equation ...
y = kx
for some constant k.
You can examine the tables to see what the value of k is by looking at ...
k = y/x
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In table A, the values of k are 125/5 = 250/10 = 500/20 = 25.
In table B, the values of k are 100/50 = 2, 250/20 = 125, 50/10 = 5. These are not constant, so the relation is not a proportional one.
In table C, the values of k are -125/5 = -250/10 = -500/20 = -25.
In table D, the values of k are 8/2 = 4, 10/4 = 2.5, 12/6 = 2. These values are not constant, so the relation is not a proportional one.
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We see that the tables of A and C both represent proportional relationships. We usually expect the value of k to be positive, but there is nothing in the definition of a proportional relationship that demands that be the case.
If this is a single-answer question, choose A.
If this is an "all that apply" question, choose A and C.