### Home > INT3 > Chapter 5 > Lesson 5.1.3 > Problem5-48

5-48.

Kirsta was working with the function machine shown at right, but when she turned her back, her little brother Caleb dropped in a number. She did not see what he dropped in, but she did see what fell out: $9$.

1. What operations must she perform on $9$ to undo what her machine did? Use this to determine what number Caleb dropped in.

What number results in $9$ after adding $5$ and then taking the square root?

2. Write an equation for a machine that will undo Kirsta’s machine.

How can you undo adding $5$ and then square rooting?