### Home > CCA2 > Chapter 1 > Lesson 1.1.2 > Problem1-14

1-14.

Terri’s project for the Math Fair was a magnificent black box that she called a function machine. If you put 3 into her machine, the output would be 8. If you put in 10, the output would be 29; and if you put in 20, it would be 59. Homework Help ✎

1. What would her machine do to the input 5? What about −1? What about x? Making an input → output table may help.

Look for a pattern.

Try making a table and graphing the points.

If the input is x, what is the output?

$\left. \begin{array} { | c | c | c | c | c | c | } \hline x & { 3 } & { 10 } & { 20 } & { 5 } & { - 1 } \\ \hline 3 x - 1 & { 8 } & { 29 } & { 59 } & { 14 } & { - 4 } \\ \hline \end{array} \right.$

2. Write an equation for Terri’s machine.

$f(x)=3x−1$