Question

If f(x) varies directly with x and f(x)= 90 when x=50, find the value of f(x) when x=10.Round you final answer to the nearest whole number. Show work

Answer 1

We know that f(x) varies directly with x, this means that the function can be written as:

`f(x)=kx`

we also know that when f(x)=90 then x=50, then we have:

`\begin{gathered} 90=50x \\ x=(90)/(50) \\ x=(9)/(5) \end{gathered}`

Hence the function is:

`f(x)=(9)/(5)x`

is x=10 then we have:

`f(10)=(9)/(5)(10)=18`

Therefore the value of f(x) is 18 when x=10