Question

Suppose y varies directly with x, and y=8 when x=4. Find x when y=10.

Answer 1

Since y varies directly with x, we have the following relation:

`(y)/(x)=k`

Where k is a constant.

For y = 8 and x = 4, we have:

`\begin{gathered} (8)/(4)=k \\ k=2 \end{gathered}`

Then, for y = 10, we have:

`\begin{gathered} (10)/(x)=2 \\ x=(10)/(2) \\ x=5 \end{gathered}`

So for y = 10 we have x = 5.