Respuesta :
Answer:
f(x)=18
Step-by-step explanation:
We are given that [tex]f(x) \propto x[/tex]
So, [tex]f(x) = kx[/tex] ---1
Where k is the constant of proportionality
f(x)=90 when x = 30
Substitute the values in Equation 1
[tex]90 = k(30)[/tex]
[tex]3 = k[/tex]
So, equation becomes : [tex]f(x) = 3x[/tex]
Now find f(x) when x = 6
Substitute x = 6 in equation 2
[tex]f(x) = 3(6)[/tex]
[tex]f(x) = 18[/tex]
Hence f(x)=18 when x = 6
