Inverse Function 892B9F
1. **State the problem:** Find the inverse function $f^{-1}(x)$ of the function $f(x) = \frac{x}{7} + 5$ and expand any brackets in the answer.
2. **Recall the formula and rules:** To find the inverse function, we swap $x$ and $y$ in the equation and then solve for $y$. The original function is $y = \frac{x}{7} + 5$.
3. **Swap variables:** Replace $f(x)$ with $y$ and swap $x$ and $y$:
$$x = \frac{y}{7} + 5$$
4. **Solve for $y$:**
Subtract 5 from both sides:
$$x - 5 = \frac{y}{7}$$
Multiply both sides by 7:
$$7(x - 5) = y$$
5. **Expand brackets:**
$$y = 7x - 35$$
6. **Write the inverse function:**
$$f^{-1}(x) = 7x - 35$$
**Explanation:** The inverse function reverses the effect of the original function. Since the original function divides by 7 and adds 5, the inverse multiplies by 7 and subtracts 35 to return to the original input.
**Final answer:**
$$f^{-1}(x) = 7x - 35$$