Answer:
Graph b
Step-by-step explanation:
Direct variation means "y varies directly as x”:
<u>Direct variation equation</u>:
where k is the (non-zero) constant of variation.
Note, therefore, that a direct variation equation <u>passes through the origin</u>, as when x = 0:
<u>Graph a</u>
y does <u>not change</u> as x varies.
Therefore this graph does <u>not</u> model a direct variation.
<u>Graph b</u>
As x gets bigger, so does y. As x gets smaller, so does y.
The line passes through the origin (0, 0).
Therefore this graph models a direct variation.
<u>Graph c</u>
x does <u>not change</u> as y varies.
Therefore this graph does <u>not</u> model a direct variation.
<u>Graph d</u>
As x gets bigger, so does y. As x gets smaller, so does y.
However, the line does <u>not</u> pass through the origin (0, 0).
Therefore this graph does <u>not</u> model a direct variation.