According to your answers, it looks like you have a solid foundation in math, however, you missed this one problem. If you had used the FOIL method and multiplied each term, you would have gotten the correct answer. If everything has been easy up to this point, then you can start with volume 5 of the Learn Math Fast System.
RESULTS: The 9th Grade Level, however, the Learn Math Fast System is for all ages. Volume 5 covers 9th - 10th grade algebra, but there is no mention of grade level within the books.