Question

If y varies inversely with x
and y is 10 when x is 5,
then what is y when x is 2?

Answer 1

25

Explanation:

y varies inversely with x, so:

y = k / x

When y is 10, x is 5:

10 = k / 5

k = 50

When x is 2:

y = 50 / 2

y = 25

Answer 2

For this case we have that if and varies inversely with x, then it is true:

`y = \frac {k} {x}`

Where:

k: It is the constant of proportionality

We have to:

`10 = \frac {k} {5}\\k = 10 * 5\\k = 50`

We find the value of y when x = 2:

`y = \frac {50} {2}\\y = 25`

Finally, we have to
`y = 25`

Answer:

`y = 25`