Respuesta :

Answer:

The value of [tex]f^{-1}(12)[/tex] is [tex]\frac{7}{-9}[/tex] .

Step-by-step explanation:

The given equation is [tex]x f(x) = 3x-7[/tex] .

[tex]f(x)=3-\frac{7}{x}[/tex]

The inverse of the function is found by adjusting the equation such that, expressing x in terms of f(x).

[tex]\frac{7}{x} = 3 - f(x)[/tex]

[tex]x = \frac{7}{3-f(x)}[/tex]

now, x = [tex]f^{-1}(x)[/tex] and f(x) be x.

Thus, [tex]f^{-1}(x) = \frac{7}{3-x}[/tex]

Now, inserting value of x as 12,

[tex]f^{-1}(12) = \frac{7}{3-(12)}[/tex]

[tex]f^{-1}(12) = \frac{7}{-9}[/tex]

Answer:

f^-1(12)=-7/9

Step-by-step explanation:

To find the inverse of a function, say f(x), follow these steps

  • Replace f(x) with y. this will make further solving easier.
  • Replace x with y and y with x.
  • Solve for y with the above equation we got in step 2.
  • Replace y with [tex]f^{-1}(x)[/tex]

So the given equation is [tex]xf(x)=3x-7[/tex]

⇒[tex]xy=3x-7[/tex]

⇒[tex]yx=3y-7[/tex]

⇒[tex]3y-xy=7[/tex]

⇒[tex]y(3-x)=7[/tex]

⇒[tex]y=\frac{7}{3-x}[/tex]

Therefore, [tex]f^{-1}(x)=\frac{7}{3-x}[/tex]

Now substitute x=12 in above equation,

[tex]f^{-1}(12)=\frac{7}{3-12} =-\frac{7}{9}[/tex]