1. **State the problem:** We are given three functions:
$$f(x) = 3 - 4x, \quad g(x) = \frac{1}{3}x - 2, \quad h(x) = \frac{2x - 3}{5x - 7}$$
We need to solve the following:
i. Find the value of $f(-3) + g(6)$.
ii. Calculate the value of $x$ for which $f(x) = 5$.
iii. Determine a simplified expression for $h^{-1}(x)$ (the inverse of $h$).
iv. Determine a simplified expression for the composite function $h(g(x))$.
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2. **Step i: Find $f(-3) + g(6)$**
Calculate $f(-3)$:
$$f(-3) = 3 - 4(-3) = 3 + 12 = 15$$
Calculate $g(6)$:
$$g(6) = \frac{1}{3} \times 6 - 2 = 2 - 2 = 0$$
Sum:
$$f(-3) + g(6) = 15 + 0 = 15$$
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3. **Step ii: Calculate $x$ such that $f(x) = 5$**
Start with the equation:
$$3 - 4x = 5$$
Subtract 3 from both sides:
$$3 - 4x - 3 = 5 - 3 \implies -4x = 2$$
Divide both sides by $-4$:
$$x = \frac{2}{\cancel{-4}} \times \cancel{-1} = -\frac{1}{2}$$
So,
$$x = -\frac{1}{2}$$
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4. **Step iii: Find the inverse function $h^{-1}(x)$**
Start with:
$$y = \frac{2x - 3}{5x - 7}$$
Swap $x$ and $y$ to find the inverse:
$$x = \frac{2y - 3}{5y - 7}$$
Multiply both sides by denominator:
$$x(5y - 7) = 2y - 3$$
Distribute:
$$5xy - 7x = 2y - 3$$
Group $y$ terms on one side:
$$5xy - 2y = 7x - 3$$
Factor out $y$:
$$y(5x - 2) = 7x - 3$$
Divide both sides by $(5x - 2)$:
$$y = \frac{7x - 3}{5x - 2}$$
Therefore,
$$h^{-1}(x) = \frac{7x - 3}{5x - 2}$$
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5. **Step iv: Find the composite function $h(g(x))$**
Recall:
$$g(x) = \frac{1}{3}x - 2$$
Substitute $g(x)$ into $h$:
$$h(g(x)) = \frac{2\left(\frac{1}{3}x - 2\right) - 3}{5\left(\frac{1}{3}x - 2\right) - 7}$$
Simplify numerator:
$$2 \times \frac{1}{3}x - 2 \times 2 - 3 = \frac{2}{3}x - 4 - 3 = \frac{2}{3}x - 7$$
Simplify denominator:
$$5 \times \frac{1}{3}x - 5 \times 2 - 7 = \frac{5}{3}x - 10 - 7 = \frac{5}{3}x - 17$$
So,
$$h(g(x)) = \frac{\frac{2}{3}x - 7}{\frac{5}{3}x - 17}$$
Multiply numerator and denominator by 3 to clear fractions:
$$h(g(x)) = \frac{2x - 21}{5x - 51}$$
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**Final answers:**
$$\boxed{\begin{cases}
f(-3) + g(6) = 15 \\
x = -\frac{1}{2} \text{ such that } f(x) = 5 \\
h^{-1}(x) = \frac{7x - 3}{5x - 2} \\
h(g(x)) = \frac{2x - 21}{5x - 51}
\end{cases}}$$
Function Operations 58237E
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