Answer: f(x) = (1/3)x + 3
This is basically in the form y = mx+b with m = 1/3 as the slope and b = 3 as the y intercept. I'm using f(x) in place of y to indicate function notation.
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Work Shown:
The goal is to solve for y.
x - 3y = -9
-3y = -9-x ... subtracting x from both sides
-3y = -x-9
y = (-x-9)/(-3) .... dividing both sides by -3
y = -x/(-3) - 9/(-3) ... break up the fraction
y = (1/3)x + 3 .... simplify
f(x) = (1/3)x + 3 .... replace y with f(x)
