### Home > PC > Chapter 1 > Lesson 1.4.2 > Problem 1-149

1-149.

Change *f*(*x*) to *y*.

Switch every *x* to *y* and every *y* to *x*.

Solve for *y*.

Composing *f* and *f*^{ −1} in either order returns the original number.

1-149.

Change *f*(*x*) to *y*.

Switch every *x* to *y* and every *y* to *x*.

Solve for *y*.

Composing *f* and *f*^{ −1} in either order returns the original number.