Question

The value of `y` varies directly with `x`, and `y=1` when `x=2`. What is `y` when `x=4`?

Answer 1

2

Explanation:

Here, `y prop x`
`rArr y = kx` where k is constant.
`rArr 1 = k.2` [put y =1,x=2]
`rArr k = 1/2`

Again, y = kx
`rArr y = 1/2×4`[put x = 4]
`rArr Y = 2`

Answer 2

`y=2`

Explanation:

`"the initial statement is "ypropx`

`"to convert to an equation multiply by k the constant"`
`"of variation"`

`rArry=kx`

`"to find k use the given condition"`

`y=1" when "x=2`

`y=kxrArrk=y/x=1/2`

`"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=1/2x)color(white)(2/2)|)))`

`"when "x=4" then"`

`y=1/2xx4=2`