Question

If y=-8 when x=-12, how do you find y when x=10 given y varies inversely as x?

Answer 1

`y=9.6`

Explanation:

Given that, `y prop 1/x.`

`:. y=k/x, k"=const. of variation."`

`:. xy=k....................(1)`

When, `x=-12, y=-8," so, by "(1), k=96.`

`:. xy=k=96, or, y=96/x.`

Hence, when `x=10, y=96/10=9.6`