Answer: f(x) = -3x + 4
Explanation:
The function is represented by
9x + 3y= 12
This is a linear equation with x as the independent variable. This means that if x is the independent variable, the y is the dependent variable. The values of y depends on the values of x. In order to represent the function, 9x + 3y= 12, we would rearrange the function such that y stands alone on the left hand side of the equation. This becomes
9x + 3y= 12
Subtracting 9x from both sides,
9x -9x + 3y = 12 - 9x
3y = 12-9x
Dividing the lefthand side and right hand side of the equation by 3, it becomes
3y/3 = (12-9x)/3
y= -3x + 4
using function notation,
y = f(x) = -3x + 4