Question

50 points please help i need it so bad

Answer 1

Answer:

D

Step-by-step explanation:

Recall that for a function $f$ such that $f:X \to Y$, where $X$ is the Domain and $Y$ is the Codomain, the function has a inverse, if and only if, $\forall y \in Y$ exist an unique $x\in X$ such that $f(x)=y$.

$\therefore f^{-1}(y)=x \iff f(x)=y$

Therefore, the inverse of $f$ for $f(x)=\dfrac{3-x}{7}$ is

$f^{-1} =3-7x$

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$f(x)=\dfrac{3-x}{7} \implies y= \dfrac{3-x}{7} \implies x=\dfrac{3-y}{7}$

$x=\dfrac{3-y}{7} \implies 7x = 3-y \implies 7x -3 = -y \implies -7x +3 = y \implies f(x)=3-7x$