I just started Geometry 3 days ago, and already have troubles. Bad sign.
Basically, we're starting the year with a few review assignments from Algebra. I had no trouble with the first, but the second covers Radicals...a subject I completely missed in school due to a 2-week-long illness. I thought I had it down, but when I went to the back of the book to check my answers, I had 8/10 of the given answers wrong.
Much panicking ensued.
So...yeah. I guess I totally messed something up, but I'm not sure what. Here's some of the problems, and my methods, and the book's answers... Am I really screwing up, or is the book wrong(Ha ha...)? If it's the former, where exactly am I screwing up so bad?
...Um...Since I don't know how to make one, "v/" will represent a Radical symbol.
1. (Answer: 11)
My method: 121 Prime Factorizes into 11 * 11. These are both prime, so it's v/11 * v/11, which equals v/11*11.
Somehow that makes 11?
I'm using what I got from the teacher's brief explanation.
2. (Answer: 2v/13)
52 PF's into 2*26. 2 is prime, and 26 PF's to 13*2. 2, 2, and 13 are prime, so it is now v/2 * v/2 * v/13. v/2 * v/2 is v/4, which is 2. So the answer is 2v/13. I got that one...?
4. (I also got 3... Answer: 6v/2)
72 PF's into 8*9. These PF into 2*4 and 3*3. 3 and 2 are prime, and 4 PF's into 2*2. So now we have 2*2*2*3*3. v/2*2*2 and v/3*3. These become v/9 and v/8. 8 has no square, so remains as v/8. v/9 becomes 3.
...So... 3v/8? I'm greatly off.
I don't get this...