To find the inverse of the function \( f(x) = 8x - 9 \), we follow these steps:
-
Replace \( f(x) \) with \( y \): \[ y = 8x - 9 \]
-
Swap \( x \) and \( y \): \[ x = 8y - 9 \]
-
Solve for \( y \): \[ x + 9 = 8y \] \[ y = \frac{x + 9}{8} \]
So, the inverse function is: \[ f^{-1}(x) = \frac{x + 9}{8} \]
Now, let's match it with the given responses:
The correct option is:
- f−1(x) is equal to the fraction with numerator (x + 9) and denominator 8.