write a linear function f with f(2)=−2 and f(1)=1

Answer 1

Since f(2) = -2, (2,-2) is a point on the line.

Since f(1) = 1, (1,1) is also a point on the line.

Slope = (-2-1) / (2-1) = -3

Equation of line: y - 1 = -3(x - 1). So, y = f(x) = -3x + 4