Question

Given f(x) = the quantity of x minus 7, divided by 3, solve for f−1(4).

Answer 1

f(x) = (x - 7)/3.

For inverse function, switch the x and y values and then solve for y.

y = (x - 7)/3 ..... this is still the original function
x = (y - 7)/3 ...... I switched the x and y
3x = y - 7
y = 3x + 7 .... this is the inverse
f⁻¹(x) = 3x + 7
f⁻¹(4) = 3(4) + 7 = 19 ... 19 is your final answer!

19

Hope this helps :)

Answer 2

f(x)=
`(x-7)/(3)`

Or , y =
`(x-7)/(3)`

→ 3 y = x-7

→ x = 3 y +7-----(1)

Now replace x by y in equation 1 ,to get the inverse of f(x)

`f^(-1)(x)= 3 x + 7`

`f^(-1)(4)= 3 * 4 +7=19`