Question

A function with an input of 1 has an output of 3. Which of the following could not be the function equation?

y = x + 2
y = 3x
y = 2x + 1
y = x - 2

Answer 1

I think it is y = x - 2 .

Answer 2

Substitute your x and y into the equations x=1 y=3
Y = x - 2
3 = 1 - 2. Is not a true statement and is your answer