Question

Y is in direct proportion to x. If x = 25 than y = 5. Find the value of y, if x = 9.

Answer 1

Given

y is in direct proportion to x.

And, if x = 25 then y = 5.

To find the value of y if x=9.

Step-by-step explanation:

It is given that,

y is in direct proportion to x.

Then,

`\begin{gathered} y\propto x \\ y=kx\text{ \_\_\_\_\_\lparen1\rparen} \end{gathered}`

Since, x=25 and y=5.

Then,

`\begin{gathered} 5=k(25) \\ k=(5)/(25) \\ k=(1)/(5) \end{gathered}`

Therefore,

`y=(1)/(5)x`

That implies, for x=9.

`\begin{gathered} y=(1)/(5)(9) \\ y=(9)/(5) \\ y=1.8 \end{gathered}`

Hence,

`y=1.8`