Answer: Choice D
[tex]f^{-1}(x) = 3-7x\\\\[/tex]
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Work Shown:
[tex]f(x) = \frac{3-x}{7}\\\\y = \frac{3-x}{7}\\\\x = \frac{3-y}{7}\\\\7x = 3-y\\\\7x+y = 3\\\\y = 3-7x\\\\f^{-1}(x) = 3-7x\\\\[/tex]
The idea is to swap each x and y, then solve for y to find the inverse.
