Question

Using this input and output machine, f(x) = ?

x3 - 13


x3 - 11


x * 20 - 11


x2 + x + 21

Answer 1

The answer is f(x)=3x-11

Answer 2

f(x)=x^3-11. this can be proved by plugging in the value 2 as x. because 2^3-11=-3, we can evidently see that b must be the correct answer.