Question

Which table has a constant of proportionality between y and x of 1/5? (from khan academy)

A.x-y
2-4/5
7-14/5
12-24/5
B.x-y
8-8/5
9-9/5
10-2
C.x-y
3-16/5
5-26/5
7-36/5

Answer 1

C

Explanation:

Solve for each choice until you get the answer 1/5.

A.

2 - 4/5

10/5 - 4/5 = 6/5; this is not 1/5

B

8 - 8/5

40/5 - 8/5 = 32/5; this is not 1/5

C

3 - 16/5

15/5 - 16/5 = -1/5

5 - 26/5

25/5 - 26/5 = -1/5

7 - 36/5

35/5 - 36/5 = -1/5; although this is negative, it still has the same proportionality of 1/5