Answer:
y = 3 - 2x
Explanation:
The function y = f(x) passes through the points (1,1) and (2,-1).
So, any two known points satisfying a linear function are sufficient to determine the function equation.
From the two points form of straight line we can write,
⇒ y - 1 = 2(1 - x)
⇒ y - 1 = 2 - 2x
⇒ y = 3 - 2x
Therefore, this is the equation of the linear function. (Answer)