Question

If y varies inversely as x and y=60 when x=80, find x when y= -20.

Answer 1

An inverse variation is defined as

`y=(k)/(x)`

Where x = 80 and y = 60, let's find k

`\begin{gathered} 60=(k)/(80) \\ k=60\cdot80=4800 \end{gathered}`

Then, we use the constant k to find x when y = -20.

`\begin{gathered} y=(4800)/(x) \\ x=(4800)/(y)=(4800)/(-20) \\ x=-240 \end{gathered}`

Hence, x is -240.