Question

If y varies inversely as (x-3). If y = 5 when x =7 find y when x=5

Answer 1

Given that y varies inversely as (x-3) .When y is 5 x is 7 . We need to find out the value of y when x is 5 .

• According to the Question ,

`\sf\longrightarrow y \propto (1)/(x-3)\\\\\sf\longrightarrow y =(k)/(x-3)`

• where k is a constant .

And ,

`\sf\longrightarrow 5 =(k)/(7)\\`

`\sf\longrightarrow k = 7*5 \\`

`\bf\longrightarrow k = 35`

Now , when x is 5 ,

`\sf\longrightarrow y = (k)/(x-3) \\`

`\sf\longrightarrow y =(35)/(5-3)\\`

`\sf\longrightarrow y=(35)/(2)\\`

`\sf\longrightarrow \boxed{\red{\sf y = 17.5 }}`