Question

If y=4 when x=14, how do you find x when y=-5 given y varies inversely as x?

Answer 1

`x=-56/5`

Explanation:

`"the initial statement is " yprop1/x`

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

`rArry=kxx1/x=k/x`

`"to find k, use the given condition"`

`y=4" when " x=14`

`y=k/xrArrk=xy=14xx4=56`

`color(red)(bar(ul(|color(white)(2/2)color(black)(y=56/x)color(white)(2/2)|)))larr" is the equation"`

`"when " y=-5`

`-5=56/xrArrx=-56/5`