Question

If w is jointly proportional to u and v, and w=2 when u=4 and v=6, what is w when u=3 and v=8?

Answer 1

`w=2`

Explanation:

`"the initial statement is "wpropuv`

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

`rArrw=kuv`

`"to find k use the given condition"`

`w=2" when "u=4" and "v=6`

`w=kuvrArrk=w/(uv)=2/24=1/12`

`"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(w=1/12uv)color(white)(2/2)|)))`

`"when "u=3" and "v=8" then"`

`w=1/12xx3xx8=1/12xx24=2`