Hi

Need help on the following:

1)Make the independent variable the subject of the equation:

This is what i have done, however i don't understand how the book's answer got

2)Simply:

Not sure how to start this.

3)Solve for x given that:

This is what i have done:

book's answer is

4)Solve for x given:

This is what i have done:

book's answer says its

P.S