Question

An equation that defines $y$ as a function of $x$ is given. Solve for $y$ in terms of $x$, and replace $y$ with the function notation $f\left(x\right)$.
$x-2y=18$

• A. $f\left(x\right)=\frac{1}{2}x-18$
• B. $f\left(x\right)=\frac{1}{2}x-9$
• C. $f\left(x\right)=-x+9$
• D. $f\left(x\right)=-\frac{1}{2}x+9$

Answer 1

Answer: (B)

$f\left(x\right)=\frac{1}{2}x-9$

$x-2y=18$

$-2y=18-x$

$y=\frac{18-x}{-2}$

$y=-(9-\frac{x}{2})$

$y=(\frac{x}{2}-9)$