Determine whether the variable y varies directly with x.

Question

x y
-1 -3
0 3
1 9
2 15
3 21
4 27

a) Yes, y does vary directly with x.
b) No, y does not vary directly with x.

Answer 1

To determine whether y varies directly with x, we can check if the ratio of y to x is constant for each pair of values.

For the given values:

-1 / -3 = 1/3
0 / 3 = 0
1 / 9 ≈ 0.111
2 / 15 ≈ 0.133
3 / 21 ≈ 0.143
4 / 27 ≈ 0.148

Since the ratio of y to x is not constant for each pair of values, we can conclude that y does not vary directly with x.

b) No, y does not vary directly with x.