Mike,
I do not understand number 6 in the absolute value section of your book. Why can’t |0| + |7| = 7? Zero is even and 7 is odd.
Mike, in your book you wrote |a| = -a ? I thought the absolute value could only be a positive number.
I don’t know how to navigate your site yet, so please forgive me if you have already answered this question. Regarding question number 8 in your book, will you further explain why y=180-x is the same angle degree as the unmarked angle? I know y=2x because of geometry, but I do not understand how y can also equal x?