Question

6. Tell whether each relationship is a direct variation. Explain your answer.
(a) The equation -18x + 7y = 0 relates the length of a videotape in centimetres x to its approximate playing
time in seconds y​

Answer 1

Answer:

Yes

Step-by-step explanation:

The given equation is a direct variation. The rule for a Direct variation is that x/y should be a constant. Another way of understanding this is that when a value gets doubled then the other value should also get doubled. In that situation it is a Direct Proportion.

This equation can be simplified in the following way:

-18x + 7y = 0

7y=18x

$\frac{x}{y} = \frac{7}{18\\}$

So it is a direct variation