### Home > A2C > Chapter 7 > Lesson 7.2.4 > Problem 7-143

7-143.

Write a rule for a machine that will undo Kirsta's machine. Call it .

Substitute *y* for

Find the inverse by switching the and the

*.*

Then solve for

*y*.

7-143.

Write a rule for a machine that will undo Kirsta's machine. Call it .

Substitute *y* for

Find the inverse by switching the and the

Then solve for